@article {KNZ001994, title = {Body size structure of soil fauna along geographic and temporal gradients of precipitation in grasslands}, journal = {Soil Biology and Biochemistry}, volume = {140}, year = {2020}, pages = {107638}, abstract = {

Precipitation is a global driver of animal abundance and diversity in terrestrial ecosystems, but we know little on how it influences the body size structure of invertebrate communities, particularly soil fauna. It is unclear whether aridity limits the abundance of large-bodied soil invertebrates, and whether temporal precipitation changes can induce local shifts. The potential role of trophic identity in modulating such relationships is also unexplored. Here we investigate the community-weighted mean body mass of soil nematodes, globally widespread invertebrates, in a two-year manipulative experiment with experimental drought and increased rainfall, conducted in three North American grassland ecosystems ranging from arid to semiarid and mesic conditions. We predict that community-weighted mean increases along with precipitation, and that long-term aridity prevents body size shifts in response to within-site temporal changes in precipitation. Nematode community-weighted mean mass increased from arid to mesic conditions. Altered precipitation within sites had much weaker effects, and none detectable in the arid site. When analysing community-weighted mean mass separately by feeding group, only plant-feeding nematodes responded positively to rainfall addition in semiarid and mesic conditions, as well as to ambient interannual differences consistently across sites, presumably due to a tighter ecological linkage with primary production. Our findings point to aridity as an environmental filter against large-bodied soil nematodes, with limited potential for community body size shifts in response to extremely dry or wet years. However, the different responses of plant-feeding taxa from other functional groups indicate potential mismatches between morphologically similar taxa in multitrophic invertebrate communities.

}, keywords = {LTER-KNZ}, doi = {10.1016/j.soilbio.2019.107638}, url = {https://linkinghub.elsevier.com/retrieve/pii/S0038071719303025}, author = {Andriuzzi, Walter S. and Franco, Andr{\'e} L.C. and Ankrom, Katharine E. and Cui, Shuyan and de Tomasel, Cecilia M. and Guan, Pingting and Gherardi, Laureano A. and Sala, Osvaldo E. and Wall, Diana H.} } @article {KNZ001946, title = {Harmony on the prairie? Grassland plant and animal community responses to variation in climate across land-use gradients}, journal = {Ecology}, volume = {101}, year = {2020}, pages = {e02986}, keywords = {LTER-KNZ}, issn = {0012-9658}, doi = {10.1002/ecy.2986}, url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/ecy.2986}, author = {Lindsey A. Bruckerhoff and Connell, R. Kent and James P. Guinnip and Adhikari, Elina and Godar, Alixandra and K. B. Gido and W. A. Boyle and Hope, Andrew G and Anthony Joern and Welti, Ellen} } @article {KNZ002001, title = {Mass ratio effects underlie ecosystem responses to environmental change}, journal = {Journal of Ecology}, volume = {108}, year = {2020}, pages = {855-864}, abstract = {


}, keywords = {LTER-KNZ}, doi = {10.1111/1365-2745.13330}, url = {https://besjournals.onlinelibrary.wiley.com/doi/abs/10.1111/1365-2745.13330}, author = {M.D. Smith and Koerner, S.E. and Alan K. Knapp and M.L. Avolio and Chaves, F.A. and Denton, E.M. and Dietrich, J. and Gibson, D.J. and Gray, J. and Hoffman, A.M. and Hoover, D.L. and Kimberly J. Komatsu and Silletti, A. and K.R. Wilcox and Yu, Q. and John M. Blair} } @article {KNZ002006, title = {Plant phylogenetic history explains in-stream decomposition at a global scale}, journal = {Journal of Ecology}, volume = {108}, year = {2020}, pages = {17-35}, abstract = {

\ \ \  1. Evolutionary history and adaptation to climate shape plant traits. Some include leaf traits that influence litter quality. Thus, evolutionary history should affect litter decomposition, a crucial ecosystem process. In addition, litter decomposition is directly influenced by climate. We consequently expect plant phylogeny, adaptation and climate to jointly influence litter decomposition. These effects and their interactions have yet to be untangled at a global scale.
\ \ \  2. Here we present an analysis of variation in litter decomposition rates in rivers and streams across 285 published studies for 239 species (from ferns to angiosperms) distributed at 494 locations world-wide. We estimated the relative contributions of climatic conditions and phylogenetic heritage on litter decomposition rates, partitioning phylogenetic from climatic effects at the site and species levels using phylogenetic eigenvector analysis and phylogenetic linear mixed models. In addition, we modelled transitions in decomposition rates under a suite of multiple adaptive-regime Ornstein\–Uhlenbeck models to test the hypothesis that natural selection has shaped clade-level litter decomposition rates.
\ \ \  3. Leaf litter decomposition rate exhibited a significant phylogenetic signal. Modelling decomposition rate as a function of location, climatic niche and phylogeny consistently recovered phylogeny alone as one of the top models in species-level analyses. Since many previous studies have focused on the same species across many locations, we also conducted analyses at the species \× site level. Both phylogenetic and climatic factors were favoured in models of this analysis, but the single most important predictor for angiosperms and for all taxa analysed together was phylogeny alone.
\ \ \  4. Synthesis. For plant species distributed globally at nearly 500 locations we found that plant phylogenetic history is a critically important predictor of litter decomposition rate in rivers and streams, explaining more of the variance in decomposition than site or climatic regime. Thus, our study demonstrates the influence of evolutionary history on suites of plant traits that shape a key ecosystem process.

}, keywords = {LTER-KNZ}, issn = {0022-0477}, doi = {10.1111/1365-2745.13262}, url = {https://besjournals.onlinelibrary.wiley.com/doi/abs/10.1111/1365-2745.13262}, author = {LeRoy, Carri J. and Hipp, Andrew L. and Lueders, Kate and Follstad Shah, Jennifer J. and Kominoski, John S. and Ard{\'o}n, Marcelo and W. K. Dodds and Gessner, Mark O. and Griffiths, Natalie A. and Lecerf, Antoine and Manning, David W. P. and Sinsabaugh, Robert L. and Webster, Jack R.}, editor = {Wardle, David} } @article {KNZ002010, title = {Soil heterogeneity increases plant diversity after twenty years of manipulation during grassland restoration}, journal = {Ecological Applications}, volume = {30}, year = {2020}, pages = {e02014}, abstract = {

The \“environmental heterogeneity hypothesis\” predicts that variability in resources promotes species coexistence, but few experiments support this hypothesis in plant communities. A previous 15-yr test of this hypothesis in a prairie restoration experiment demonstrated a weak effect of manipulated soil resource heterogeneity on plant diversity. This response was attributed to a transient increase in richness following a post-restoration supplemental propagule addition, occasionally higher diversity under nutrient enrichment, and reduced cover of a dominant species in a subset of soil treatments. Here, we report community dynamics under continuous propagule addition in the same experiment, corresponding to 16\–20 yr of restoration, in response to altered availability and heterogeneity of soil resources. We also quantified traits of newly added species to determine if heterogeneity increases the amount and variety of niches available for new species to exploit. The heterogeneous treatment contained a factorial combination of altered nutrient availability and soil depth; control plots had no manipulations. Total diversity and richness were higher in the heterogeneous treatment during this 5-yr study due to higher cover, diversity, and richness of previously established forbs, particularly in the N-enriched subplots. All new species added to the experiment exhibited unique trait spaces, but there was no evidence that heterogeneous plots contained a greater variety of new species representing a wider range of trait spaces relative to the control treatment. The richness and cover of new species was higher in N-enriched soil, but the magnitude of this response was small. Communities assembling under long-term N addition were dominated by different species among subplots receiving added N, leading to greater dispersion of communities among the heterogeneous relative to control plots. Contrary to the deterministic mechanism by which heterogeneity was expected to increase diversity (greater variability in resources for new species to exploit), higher diversity in the heterogeneous plots resulted from destabilization of formerly grass-dominated communities in N-enriched subplots. While we do not advocate increasing available soil N at large scales, we conclude that the positive effect of environmental heterogeneity on diversity can take decades to materialize and depend on development of stochastic processes in communities with strong establishment limitation.

}, keywords = {LTER-KNZ}, author = {S.G. Baer and T. Adams and Scott, D.A. and John M. Blair and Scott. L. Collins} } @article {5802, title = {Soil structure~is an important omission in Earth System Models}, journal = {Nature Communications}, volume = {11}, year = {2020}, abstract = {

Most soil hydraulic information used in Earth System Models (ESMs) is derived from pedo-transfer functions that use easy-to-measure soil attributes to estimate hydraulic parameters. This parameterization relies heavily on soil texture, but overlooks the critical role of soil structure originated by soil biophysical activity. Soil structure omission is pervasive also in sampling and measurement methods used to train pedotransfer functions. Here we show how systematic inclusion of salient soil structural features of biophysical origin affect local and global hydrologic and climatic responses. Locally, including soil structure in models significantly alters infiltration-runoff partitioning and recharge in wet and vegetated regions. Globally, the coarse spatial resolution of ESMs and their inability to simulate intense and short rainfall events mask effects of soil structure on surface fluxes and climate. Results suggest that although soil structure affects local hydrologic response, its implications on global-scale climate remains elusive in current ESMs.

}, keywords = {LTER-KNZ}, doi = {10.1038/s41467-020-14411-z}, url = {http://www.nature.com/articles/s41467-020-14411-z}, author = {Fatichi, Simone and Or, Dani and Walko, Robert and Vereecken, Harry and Young, Michael H. and Ghezzehei, Teamrat A. and Hengl, Tomislav and Kollet, Stefan and Agam, Nurit and Avissar, Roni} } @article {KNZ001945, title = {Belowground biomass response to nutrient enrichment depends on light limitation across globally distributed grasslands}, journal = {Ecosystems}, volume = {22}, year = {2019}, pages = {1466{\textendash}1477}, abstract = {

Anthropogenic activities are increasing nutrient inputs to ecosystems worldwide, with consequences for global carbon and nutrient cycles. Recent meta-analyses show that aboveground primary production is often co-limited by multiple nutrients; however, little is known about how root production responds to changes in nutrient availability. At twenty-nine grassland sites on four continents, we quantified shallow root biomass responses to nitrogen (N), phosphorus (P) and potassium plus micronutrient enrichment and compared below- and aboveground responses. We hypothesized that optimal allocation theory would predict context dependence in root biomass responses to nutrient enrichment, given variation among sites in the resources limiting to plant growth (specifically light versus nutrients). Consistent with the predictions of optimal allocation theory, the proportion of total biomass belowground declined with N or P addition, due to increased biomass aboveground (for N and P) and decreased biomass belowground (N, particularly in sites with low canopy light penetration). Absolute root biomass increased with N addition where light was abundant at the soil surface, but declined in sites where the grassland canopy intercepted a large proportion of incoming light. These results demonstrate that belowground responses to changes in resource supply can differ strongly from aboveground responses, which could significantly modify predictions of future rates of nutrient cycling and carbon sequestration. Our results also highlight how optimal allocation theory developed for individual plants may help predict belowground biomass responses to nutrient enrichment at the ecosystem scale across wide climatic and environmental gradients.

}, keywords = {LTER-KNZ, belowground biomass, Fertilization, nitrogen, Nutrient Network, optimal allocation, phosphorus roots}, doi = {10.1007/s10021-019-00350-4}, url = {https://link.springer.com/article/10.1007\%2Fs10021-019-00350-4}, author = {Cleland, Elsa E. and Lind, Eric M. and DeCrappeo, Nicole M. and DeLorenze, Elizabeth and Wilkins, Rachel Abbott and P. Adler and Bakker, Jonathan D. and Brown, Cynthia S. and Davies, Kendi F. and Esch, Ellen and Firn, Jennifer and Gressard, Scott and Gruner, Daniel S. and Hagenah, Nicole and Harpole, W. Stanley and Hautier, Yann and Hobbie, Sarah E. and Hofmockel, Kirsten S. and Kirkman, Kevin and Knops, Johannes and Kopp, Christopher W. and Kimberly J. La Pierre and MacDougall, Andrew and McCulley, Rebecca L. and Melbourne, Brett A. and Joslin L. Moore and Prober, Suzanne M. and Riggs, Charlotte and Risch, Anita C. and Schuetz, Martin and Stevens, Carly and Wragg, Peter D. and Wright, Justin and E.T. Borer and Seabloom, Eric W.} } @article {KNZ001948, title = {Building an integrated infrastructure for exploring biodiversity: field collections and archives of mammals and parasites}, journal = {Journal of Mammalogy}, volume = {100}, year = {2019}, pages = {382 - 393}, abstract = {


}, keywords = {LTER-KNZ}, doi = {10.1093/jmammal/gyz048}, url = {https://academic.oup.com/jmammal/article/100/2/382/5436909}, author = {Galbreath, Kurt E and Hoberg, Eric P and Cook, Joseph A and Armi{\'e}n, Blas and Bell, Kayce C and Campbell, Mariel L and Dunnum, Jonathan L and Dursahinhan, Altangerel T and Eckerlin, Ralph P and Gardner, Scott L and Greiman, Stephen E and Henttonen, Heikki and Jim{\'e}nez, Agust{\'\i}n and Koehler, Anson V A and Nyamsuren, Batsaikhan and Tkach, Vasyl V and Torres-P{\'e}rez, Fernando and Tsvetkova, Albina and Hope, Andrew G} } @article {KNZ001950, title = {Characterizing grassland fire activity in the Flint Hills region and air quality using satellite and routine surface monitor data}, journal = {Science of The Total Environment}, volume = {659}, year = {2019}, pages = {1555 - 1566}, abstract = {

Prescribed grassland fires in the Flint Hills region of central Kansas and northern Oklahoma are a common tool for land management. Local to regional scale impacts on air quality from grassland fires in this region are not well understood, which is important as these types of prescribed fires may increase in the future to preserve broader areas of native grasses in the central U.S. Routine air quality and deposition measurements from sites in and near the Flint Hills were examined for coincident increases during periods of increased prescribed grassland fires. Prescribed fire activity in this region was quantified using satellite detections and multiple publicly available data products of area burned information. March and April comprise over half (41 to 93\%) of all annual fire detections in the Flint Hills region seen from satellites between 2007 and 2018 excluding drought years. Annual total fire detections in this region range between 1 and 12 thousand and account for approximately 3\% of all fire detections in the contiguous U.S. Annual acres burned ranged from 0.2 to 2 million acres based on U.S. EPA\&$\#$39;s National Emission Inventory, which accounts for 4 to 38\% of grasslands in the area. A comparison of weekly standardized anomalies suggests a relationship between periods of increased grassland fire activity and elevated levels of PM2.5 organic carbon, elemental carbon, and potassium. Daily 1-hr maximum ozone (O3), ammonia (NH3), sulfur dioxide (SO2), and oxidized nitrogen gases measured at Konza Prairie also had increased levels when prescribed grassland fire activity was highest. This detailed characterization of prescribed fire activity in the Flint Hills and associated air quality impacts will benefit future efforts to understand changes in atmospheric composition due to changing land management practices.

}, keywords = {LTER-KNZ}, issn = {00489697}, doi = {10.1016/j.scitotenv.2018.12.427}, url = {https://www.sciencedirect.com/science/article/pii/S0048969718353221?via\%3Dihub}, author = {Baker, K.R. and Koplitz, S.N. and Foley, K.M. and Avey, L. and Hawkins, A.} } @article {KNZ001953, title = {A comprehensive approach to analyzing community dynamics using rank abundance curves}, journal = {Ecosphere}, volume = {10}, year = {2019}, pages = {e02881}, abstract = {


}, keywords = {LTER-KNZ}, doi = {10.1002/ecs2.2881}, url = {https://esajournals.onlinelibrary.wiley.com/doi/epdf/10.1002/ecs2.2881}, author = {M.L. Avolio and Carroll, I. and Scott. L. Collins and Houseman, Gregory R. and Hallett, L.M. and Isbell, F.L. and Koerner, S.E. and Kimberly J. Komatsu and M.D. Smith and K.R. Wilcox} } @article {KNZ001938, title = {Demystifying dominant species}, journal = {New Phytologist}, volume = {223}, year = {2019}, pages = {1106 - 1126}, abstract = {


}, keywords = {LTER-KNZ}, doi = {10.1111/nph.15789}, url = {https://onlinelibrary.wiley.com/doi/abs/10.1111/nph.15789}, author = {M.L. Avolio and Forrestel, Elisabeth J. and Chang, Cynthia C. and Kimberly J. La Pierre and Burghardt, Karin T. and M.D. Smith} } @article {KNZ001965, title = {Global change effects on plant communities are magnified by time and the number of global change factors imposed}, journal = {Proceedings of the National Academy of Sciences}, volume = {116}, year = {2019}, pages = {17867-17873}, abstract = {



River ecosystems receive and process vast quantities of terrestrial organic carbon, the fate of which depends strongly on microbial activity. Variation in and controls of processing rates, however, are poorly characterized at the global scale. In response, we used a peer-sourced research network and a highly standardized carbon processing assay to conduct a global-scale field experiment in greater than 1000 river and riparian sites. We found that Earth\’s biomes have distinct carbon processing signatures. Slow processing is evident across latitudes, whereas rapid rates are restricted to lower latitudes. Both the mean rate and variability decline with latitude, suggesting temperature constraints toward the poles and greater roles for other environmental drivers (e.g., nutrient loading) toward the equator. These results and data set the stage for unprecedented \“next-generation biomonitoring\” by establishing baselines to help quantify environmental impacts to the functioning of ecosystems at a global scale.

}, keywords = {LTER-KNZ}, doi = {10.1126/sciadv.aav0486}, url = {http://advances.sciencemag.org/content/5/1/eaav0486}, author = {Tiegs, Scott D. and Costello, David M. and Isken, Mark W. and Woodward, Guy and McIntyre, Peter B. and Gessner, Mark O. and Chauvet, Eric and Griffiths, Natalie A. and Flecker, Alex S. and Acu{\~n}a, Vicenc and Albari{\~n}o, Ricardo and Allen, Daniel C. and Alonso, Cecilia and Andino, Patricio and Arango, Clay and Aroviita, Jukka and Barbosa, Marcus V. M. and Barmuta, Leon A. and Baxter, Colden V. and Bell, Thomas D. C. and Bellinger, Brent and Boyero, Luz and Brown, Lee E. and Bruder, Andreas and Bruesewitz, Denise A. and Burdon, Francis J. and Callisto, Marcos and Canhoto, Cristina and Capps, Krista A. and Castillo, Mar{\'\i}a M. and Clapcott, Joanne and Colas, Fanny and Col{\'o}n-Gaud, Checo and Cornut, Julien and Crespo-P{\'e}rez, Ver{\'o}nica and Cross, Wyatt F. and Culp, Joseph M. and Danger, Michael and Dangles, Olivier and de Eyto, Elvira and Derry, Alison M. and Villanueva, {\'\i}az and Douglas, Michael M. and Elosegi, Arturo and Encalada, Andrea C. and Entrekin, Sally and Espinosa, Rodrigo and Ethaiya, Diana and Ferreira, Ver{\'o}nica and Ferriol, Carmen and Flanagan, Kyla M. and Fleituch, Tadeusz and Follstad Shah, Jennifer J. and Frainer Barbosa, Andr{\'e} and Friberg, Nikolai and Frost, Paul C. and Garcia, Erica A. and Garc{\'\i}a Lago, Liliana and Garc{\'\i}a Soto, Pavel Ernesto and Ghate, Sudeep and Giling, Darren P. and Gilmer, Alan and {\c c}alves, Jos{\'e} Francisco and Gonzales, Rosario Karina and Graca, Manuel A. S. and Grace, Mike and Grossart, Hans-Peter and Guerrold, Francois and Gulis, Vlad and Hepp, Luiz U. and Higgins, Scott and Hishi, Takuo and Huddart, Joseph and Hudson, John and Imberger, Samantha and {\~n}iguez-Armijos, Carlos and Iwata, Tomoya and Janetski, David J. and Jennings, Eleanor and Kirkwood, Andrea E. and Koning, Aaron A. and Kosten, Sarian and Kuehn, Kevin A. and Laudon, Hjalmar and Leavitt, Peter R. and Lemes da Silva, Aurea L. and Leroux, Shawn J. and LeRoy, Carri J. and Lisi, Peter J. and MacKenzie, Richard and Marcarelli, Amy M. and Masese, Frank O. and McKie, Brendan G. and Oliveira Medeiros, Adriana and Meissner, Kristian and Mili{\v s}a, Marko and Mishra, Shailendra and Miyake, Yo and Moerke, Ashley and Mombrikotb, Shorok and Mooney, Rob and Moulton, Tim and Muotka, Timo and Negishi, Junjiro N. and Neres-Lima, Vinicius and Nieminen, Mika L. and Nimptsch, Jorge and Ondruch, Jakub and Paavola, Riku and Pardo, Isabel and Patrick, Christopher J. and Peeters, Edwin T. H. M. and Pozo, Jesus and Pringle, Catherine and Prussian, Aaron and Quenta, Estefania and Quesada, Antonio and Reid, Brian and Richardson, John S. and Rigosi, Anna and Rinc{\'o}n, Jos{\'e} and Risnoveanu, Geta and Robinson, Christopher T. and Rodr{\'\i}guez-Gallego, Lorena and Royer, Todd V. and Rusak, James A. and Santamans, Anna C. and Selmeczy, G{\'e}za B. and Simiyu, Gelas and Skuja, Agnija and Smykla, Jerzy and Sridhar, Kandikere R. and Sponseller, Ryan and Stoler, Aaron and Swan, Christopher M. and Szlag, David and Mello, Franco Teixeira-de and Tonkin, Jonathan D. and Uusheimo, Sari and Veach, Allison M. and Vilbaste, Sirje and Vought, Lena B. M. and Wang, Chiao-Ping and Webster, Jackson R. and Wilson, Paul B. and Woelfl, Stefan and Xenopoulos, Marguerite A. and Yates, Adam G. and Yoshimura, Chihiro and Yule, Catherine M. and Zhang, Yixin X. and Zwart, Jacob A.} } @article {KNZ001968, title = {Habitat selection and space use of Upland Sandpipers at nonbreeding grounds}, journal = {Avian Conservation and Ecology}, volume = {14}, year = {2019}, pages = {14:art18}, abstract = {

Habitat requirements of migratory birds can be dynamic during the annual cycle, and understanding habitat use during the nonbreeding season is important for conservation planning. In grassland birds, habitat selection is often determined by features of vegetative structure that are associated with predation risk, food resources, or thermal environments. And, these habitats are affected by anthropogenic influences such as agriculture conversion and production of livestock. In our four-year field study, we examined the space use and habitat selection of Upland Sandpipers (Bartramia longicauda) during the nonbreeding season in an area of private grasslands managed for livestock production within the Northern Campos ecoregion of Uruguay. We radio-tracked sandpipers during the nonbreeding season to test the hypothesis that space use, habitat selection, and flock size were determined by vegetative structure in managed grasslands with different grazing and agricultural management regimes. We captured and tagged 62 sandpipers during the nonbreeding season in the austral summer, and recorded a total of 506 locations for our sample of radio-marked birds. Foraging Upland Sandpipers primarily selected two types of native grasslands associated with shallow, rocky soils. The vegetation configuration of disturbed pastures were open landscapes that were good for detection of arthropod prey but offered little cover for avoidance of predators. Sandpipers were usually found in small groups of 2\–20 birds, and the largest flocks of 40\–50 birds were found in pastures with relatively short grass cover (20 to 40\% tall grass cover). Low to moderate stocking densities of domestic livestock created variation in vegetation height and cover in large areas and allowed for coexistence of grassland birds with different habitat requirements. Upland Sandpipers preferred disturbed areas, which may not support the needs of other species of grasslands birds. Our results emphasize the need for habitat heterogeneity and disturbance forces such as grazing in grassland systems. Our research contributes new information on the ecology of migratory grassland birds and provides insights for biodiversity conservation on private lands used for livestock production.

}, keywords = {LTER-KNZ}, doi = {10.5751/ACE-01461-140218}, url = {https://brage.nina.no/nina-xmlui/handle/11250/2632763}, author = {M. Alfaro-Barrios and Liguori, L. and Sandercock, B.K. and Berazategui, M. and Arim, M.} } @article {KNZ001970, title = {How ecologists define drought, and why we should do better}, journal = {Global Change Biology}, volume = {25}, year = {2019}, pages = {3193 - 3200}, abstract = {

Drought, widely studied as an important driver of ecosystem dynamics, is predicted to increase in frequency and severity globally. To study drought, ecologists must define or at least operationalize what constitutes a drought. How this is accomplished in practice is unclear, particularly given that climatologists have long struggled to agree on definitions of drought, beyond general variants of \“an abnormal deficiency of water.\” We conducted a literature review of ecological drought studies (564 papers) to assess how ecologists describe and study drought. We found that ecologists characterize drought in a wide variety of ways (reduced precipitation, low soil moisture, reduced streamflow, etc.), but relatively few publications (~32\%) explicitly define what are, and are not, drought conditions. More troubling, a surprising number of papers (~30\%) simply equated \“dry conditions\” with \“drought\” and provided little characterization of the drought conditions studied. For a subset of these, we calculated Standardized Precipitation Evapotranspiration Index values for the reported drought periods. We found that while almost 90\% of the studies were conducted under conditions quantifiable as slightly to extremely drier than average, ~50\% were within the range of normal climatic variability. We conclude that the current state of the ecological drought literature hinders synthesis and our ability to draw broad ecological inferences because drought is often declared but is not explicitly defined or well characterized. We suggest that future drought publications provide at least one of the following: (a) the climatic context of the drought period based on long-term records; (b) standardized climatic index values; (c) published metrics from drought-monitoring organizations; (d) a quantitative definition of what the authors consider to be drought conditions for their system. With more detailed and consistent quantification of drought conditions, comparisons among studies can be more rigorous, increasing our understanding of the ecological effects of drought.

}, keywords = {LTER-KNZ}, doi = {10.1111/gcb.14747}, url = {https://onlinelibrary.wiley.com/doi/abs/10.1111/gcb.14747}, author = {Slette, Ingrid J. and Post, Alison K. and Awad, Mai and Even, Trevor and Punzalan, Arianna and Williams, Sere and M.D. Smith and Alan K. Knapp} } @article {KNZ001974, title = {Management regime and habitat response influence abundance of regal fritillary (Speyeria idalia) in tallgrass prairie}, journal = {Ecosphere}, volume = {10}, year = {2019}, pages = {e02845}, abstract = {

The \>2,570,000-ha Flint Hills ecoregion of Kansas, USA, harbors the largest remaining contiguous tract of tallgrass prairie in North America, a unique system, as the remainder of North America\&$\#$39;s tallgrass prairie has succumbed to development and conversion. Consequently, the loss and degradation of tallgrass prairie has reduced populations of many North American prairie-obligate species including the regal fritillary (Speyeria idalia) butterfly. Population abundance and occupied range of regal fritillary have declined \>99\%, restricting many populations to isolated, remnant patches of tallgrass prairie. Such extensive decline has resulted in consideration of the regal fritillary for protection under the Endangered Species Act. Although it is widely accepted that management practices such as fire, grazing, and haying are necessary to maintain prairie ecosystems, reported responses by regal fritillary to these management regimes have been ambiguous. We tested effects of prescribed fire across short, moderate, and long fire-return intervals as well as grazing and haying management treatments on regal fritillary density. We also tested the relative influence of habitat characteristics created by these management regimes by measuring density of an obligate host plant (Viola spp.) and canopy cover of woody vegetation, grasses, forbs/ferns, bare ground, and litter. We found density was at least 1.6 times greater in sites burned with a moderate fire-return interval vs. sites burned with short and long fire-return intervals. Overall management regardless of fire-return interval did not have an effect on density. Percent cover of grass had the strongest positive association, while percent cover of woody vegetation had the greatest negative effect on density. Our results indicate that patch-burning is a viable and perhaps even ideal management strategy for regal fritillary in tallgrass prairie landscapes. Additionally, these results elucidate the importance of fire, particularly when applied at moderate-return intervals to regal fritillary, and corroborate a growing suite of studies that suggest fire is perhaps not as detrimental to populations of regal fritillary as previously believed.

}, keywords = {LTER-KNZ}, doi = {10.1002/ecs2.2019.10.issue-810.1002/ecs2.2845}, url = {https://onlinelibrary.wiley.com/toc/21508925/10/8}, author = {McCullough, K. and Gene Albanese and David A. Haukos and Ricketts, A. M. and Stratton, S.} } @article {KNZ001939, title = {More salt, please: global patterns, responses and impacts of foliar sodium in grasslands}, journal = {Ecology Letters}, volume = {22}, year = {2019}, note = {


}, pages = {1136 - 1144}, abstract = {


}, keywords = {LTER-KNZ}, issn = {1461-023X}, doi = {10.1111/ele.13270}, url = {https://onlinelibrary.wiley.com/doi/abs/10.1111/ele.13270}, author = {E.T. Borer and Lind, E. M. and Firn, J. and Seabloom, E. W. and Anderson, T. M. and Bakker, E. S. and L.A. Biederman and Kimberly J. La Pierre and MacDougall, A. S. and Joslin L. Moore and C. W. Rice and sch{\"u}tz, M. and Stevens, C. J.} } @article {KNZ001985, title = {Soil net nitrogen mineralisation across global grasslands}, journal = {Nature Communications}, volume = {10}, year = {2019}, abstract = {


}, keywords = {LTER-KNZ}, doi = {10.1038/s41467-019-12948-2}, url = {http://www.nature.com/articles/s41467-019-12948-2}, author = {C. W. Rice and Zimmermann, S. and Ochoa-Hueso, R. and sch{\"u}tz, M. and Frey, B. and Firn, J. L. and Fay, P. A. and Hagedorn, F. and E.T. Borer and Seabloom, E. W. and Harpole, W. S. and Knops, J. M. H. and McCulley, R. L. and Broadbent, A. A. D. and Stevens, C. J. and Silveira, M. L. and P. Adler and B{\'a}ez, S. and L.A. Biederman and John M. Blair and Brown, C. S. and Caldeira, M. C. and Scott. L. Collins and Daleo, P. and di Virgilio, A. and Ebeling, A. and Eisenhauer, N. and Esch, E. and Eskelinen, A. and Hagenah, N. and Hautier, Y. and Kirkman, K. P. and MacDougall, A. S. and Joslin L. Moore and Power, S. A. and Prober, S. M. and Roscher, C. and Sankaran, M. and Siebert, J. and Speziale, K. L. and Tognetti, P. M. and Virtanen, R. and Yahdjian, L. and Moser, B.} } @article {KNZ001898, title = {Ambient changes exceed treatment effects on plant species abundance in long-term global change experiments}, journal = {Glob Chang Biol}, volume = {24}, year = {2018}, pages = {5668 - 5679}, abstract = {






}, keywords = {LTER-KNZ}, doi = {10.1111/jav.01480}, url = {https://onlinelibrary.wiley.com/doi/full/10.1111/jav.01480}, author = {M. Alfaro-Barrios and Sandercock, B.K. and Liguori, Luciano and Arim, Matias} } @article {KNZ001888, title = {Change in dominance determines herbivore effects on plant biodiversity}, journal = {Nature Ecology and Evolution}, volume = {2}, year = {2018}, pages = {1925-1932}, abstract = {


}, keywords = {LTER-KNZ}, doi = {https://doi.org/10.1038/s41559-018-0696-y}, url = {https://www.nature.com/articles/s41559-018-0696-y$\#$article-info}, author = {Koerner, S.E. and M.D. Smith and Burkepile, D.E. and N.P. Hanan and M.L. Avolio and Scott. L. Collins and Alan K. Knapp and N.P. Lemoine and E.J. Forrestel and S. Eby and D.I. Thompson and G. Aguado-Santacruz and J.P. Anderson and Anderson, M. and A. Angassa and S. Bagchi and E.S. Bakker and Bastin, Gary and L.E. Baur and K.H. Beard and E.A. Beever and P.J. Bohlen and Elizabeth H. Boughton and Canestro, Don and Cesa, Ariela and Chaneton, Enrique and Cheng, Jimin and C.M. D{\textquoteright}Antonio and C. Deleglise and Fadiala. Demb{\'e}l{\'e} and Josh. Dorrough and David. J. Eldridge and Barbara. Fernandez-Going and Silvia. Fern{\'a}ndez-Lugo and Lauchlan. H. Fraser and Bill. Freedman and Gonzalo. Garc{\'\i}a-Salgado and Jacob. R. Goheen and Liang. Guo and Sean. Husheer and Moussa. Karemb{\'e} and Johannes. M. H. Knops and Tineke. Kraaij and Andrew. Kulmatiski and Minna-Maarit. Kyt{\"o}viita and Felipe. Lezama and Gregory. Loucougaray and Alejandro. Loydi, Dan G. Milchunas, and Dan.G. Milchunas, and Suzanne. J. Milton and J.W. Morgan and Claire. Moxham and Kyle. C. Nehring and Han. Olff and Todd. M. Palmer and Salvador. Rebollo and Corinna. Riginos and Anita. C. Risch and Marta Rueda and Mahesh. Sankaran and Takehiro. Sasaki and Kathryn. A. Schoenecker and Nick. L. Schultz and Martin. Sch{\"u}tz and Angelika. Schwabe and Frances. Siebert and Christian. Smit and Karen. A. Stahlheber and Christian. Storm and Dustin. J. Strong and Jishuai. Su and Yadugiri. V. Tiruvaimozhi and Claudia. Tyler and James. Val and Martijn. L. Vandegehuchte and Kari. E. Veblen and Lance. T. Vermeire and David. Ward and Jianshuang. Wu and Truman. P. Young and Qiang. Yu and Tamara. Jane. Zelikova} } @article {KNZ001865, title = {Codominant grasses differ in gene expression under experimental climate extremes in native tallgrass prairie}, journal = {PeerJ}, year = {2018}, pages = {e4394}, abstract = {

Extremes in climate, such as heat waves and drought, are expected to become more frequent and intense with forecasted climate change. Plant species will almost certainly differ in their responses to these stressors. We experimentally imposed a heat wave and drought in the tallgrass prairie ecosystem near Manhattan, Kansas, USA to assess transcriptional responses of two ecologically important C4 grass species, Andropogon gerardii and Sorghastrum nutans. Based on previous research, we expected that S. nutans would regulate more genes, particularly those related to stress response, under high heat and drought. Across all treatments, S. nutans showed greater expression of negative regulatory and catabolism genes while A. gerardii upregulated cellular and protein metabolism. As predicted, S. nutans showed greater sensitivity to water stress, particularly with downregulation of non-coding RNAs and upregulation of water stress and catabolism genes. A. gerardii was less sensitive to drought, although A. gerardii tended to respond with upregulation in response to drought versus S. nutans which downregulated more genes under drier conditions. Surprisingly, A. gerardii only showed minimal gene expression response to increased temperature, while S. nutans showed no response. Gene functional annotation suggested that these two species may respond to stress via different mechanisms. Specifically, A. gerardii tends to maintain molecular function while S. nutans prioritizes avoidance. Sorghastrum nutans may strategize abscisic acid response and catabolism to respond rapidly to stress. These results have important implications for success of these two important grass species under a more variable and extreme climate forecast for the future.

}, keywords = {LTER-KNZ}, doi = {https://doi.org/10.7717/peerj.4394}, url = {https://peerj.com/articles/4394/}, author = {Hoffman, Ava M. and M.L. Avolio and Alan K. Knapp and M.D. Smith} } @article {KNZ001918, title = {Continental-scale decrease in net primary productivity in streams due to climate warming}, journal = {Nature Geoscience}, volume = {11}, year = {2018}, pages = {415 - 420}, abstract = {

Streams play a key role in the global carbon cycle. The balance between carbon intake through photosynthesis and carbon release via respiration influences carbon emissions from streams and depends on temperature. However, the lack of a comprehensive analysis of the temperature sensitivity of the metabolic balance in inland waters across latitudes and local climate conditions hinders an accurate projection of carbon emissions in a warmer future. Here, we use a model of diel dissolved oxygen dynamics, combined with high-frequency measurements of dissolved oxygen, light and temperature, to estimate the temperature sensitivities of gross primary production and ecosystem respiration in streams across six biomes, from the tropics to the arctic tundra. We find that the change in metabolic balance, that is, the ratio of gross primary production to ecosystem respiration, is a function of stream temperature and current metabolic balance. Applying this relationship to the global compilation of stream metabolism data, we find that a 1\ \°C increase in stream temperature leads to a convergence of metabolic balance and to a 23.6\% overall decline in net ecosystem productivity across the streams studied. We suggest that if the relationship holds for similarly sized streams around the globe, the warming-induced shifts in metabolic balance will result in an increase of 0.0194\ Pg carbon emitted from such streams every year.

}, keywords = {LTER-KNZ}, doi = {10.1038/s41561-018-0125-5}, url = {http://www.nature.com/articles/s41561-018-0125-5}, author = {Song, Chao and W. K. Dodds and R{\"u}egg, Janine and Argerich, Alba and Baker, Christina L. and W.B. Bowden and Douglas, Michael M. and Farrell, Kaitlin J. and Flinn, Michael B. and Garcia, Erica A. and Helton, Ashley M. and Harms, Tamara K. and Jia, Shufang and Jones, Jeremy B. and Koenig, Lauren E. and Kominoski, John S. and McDowell, William H. and McMaster, Damien and Parker, Samuel P. and Rosemond, Amy D. and Ruffing, Claire M. and Sheehan, Ken R. and Trentman, Matt T. and M.R. Whiles and Wollheim, Wilfred M. and Ballantyne, Ford} } @article {KNZ001899, title = {Linking gene regulation, physiology, and plant biomass allocation in Andropogon gerardii in response to drought}, journal = {Plant Ecology}, volume = {219}, year = {2018}, pages = {1 - 15}, abstract = {

Plant responses to drought are often initiated at the molecular level and cascade upwards to affect physiology and growth. How plants respond to and recover from drought have consequences for their growth and survival in drier climates predicted with climate change. We studied four ecologically relevant genotypes of a common C4 grass, Andropogon gerardii. These genotypes had differential responses to a decade of more variable precipitation patterns in a field experiment in native tallgrass prairie. Here, we conducted a greenhouse experiment examining how these genotypes responded to repeated 10-day drought-recovery cycles when experiencing either a severe or moderate drought. We did this twice over the course of the experiment, early, after 5\ weeks, and late, after 9\ weeks of drought. We studied nine genes involved in water stress signaling and drought response in leaf tissue using real-time reverse-transcriptase polymerase chain reaction (qRT-PCR). We also measured photosynthesis, stomatal conductance, and biomass accumulation and allocation. In early drought, we found consistent differences among genotypes in gene expression, leaf-level physiology, and biomass accumulation and allocation. We found genes involved in ABA, proline synthesis, and mitigating oxidative stress were differentially expressed between genotypes, while genes that coded for aquaporins and chaperones were not. In late drought, we found fewer overall differences, and little regulation of drought responsive genes. Ultimately, we found genotypes either had greater phenotypic plasticity, suggesting an ability to avoid drought and maximize water resources when they were present, or genotypes were better at tolerating drought.

}, keywords = {LTER-KNZ}, doi = {10.1007/s11258-017-0773-3}, url = {http://link.springer.com/10.1007/s11258-017-0773-3}, author = {M.L. Avolio and Hoffman, Ava M. and M.D. Smith} } @article {KNZ001894, title = {Local loss and spatial homogenization of plant diversity reduce ecosystem multifunctionality}, journal = {Nature Ecology \& Evolution}, volume = {2}, year = {2018}, pages = {50-56}, abstract = {

Biodiversity is declining in many local communities while also becoming increasingly homogenized across space. Experiments show that local plant species loss reduces ecosystem functioning and services, but the role of spatial homogenization of community composition and the potential interaction between diversity at different scales in maintaining ecosystem functioning remains unclear, especially when many functions are considered (ecosystem multifunctionality). We present an analysis of eight ecosystem functions measured in 65 grasslands worldwide. We find that more diverse grasslands\—those with both species-rich local communities (α-diversity) and large compositional differences among localities (β-diversity)\—had higher levels of multifunctionality. Moreover, α- and β-diversity synergistically affected multifunctionality, with higher levels of diversity at one scale amplifying the contribution to ecological functions at the other scale. The identity of species influencing ecosystem functioning differed among functions and across local communities, explaining why more diverse grasslands maintained greater functionality when more functions and localities were considered. These results were robust to variation in environmental drivers. Our findings reveal that plant diversity, at both local and landscape scales, contributes to the maintenance of multiple ecosystem services provided by grasslands. Preserving ecosystem functioning therefore requires conservation of biodiversity both within and among ecological communities.

}, keywords = {LTER-KNZ}, doi = {10.1038/s41559-017-0395-0}, url = {http://www.nature.com/articles/s41559-017-0395-0}, author = {Hautier, Yann and Isbell, Forest and E.T. Borer and Seabloom, Eric W. and Harpole, W. Stanley and Lind, Eric M. and MacDougall, Andrew S. and Stevens, Carly J. and P. Adler and J. Alberti and Bakker, Jonathan D. and Brudvig, Lars A. and Buckley, Yvonne M. and Cadotte, Marc and Caldeira, Maria C. and Chaneton, Enrique J. and Chu, Chengjin and Daleo, Pedro and Dickman, Christopher R. and Dwyer, John M. and Eskelinen, Anu and Fay, Philip A. and Firn, Jennifer and Hagenah, Nicole and Hillebrand, Helmut and Iribarne, Oscar and Kirkman, Kevin P. and Knops, Johannes M. H. and Kimberly J. La Pierre and McCulley, Rebecca L. and J.W. Morgan and P{\"a}rtel, Meelis and Pascual, Jesus and Price, Jodi N. and Prober, Suzanne M. and Risch, Anita C. and Sankaran, Mahesh and Schuetz, Martin and Standish, Rachel J. and Virtanen, Risto and Wardle, Glenda M. and Yahdjian, Laura and Hector, Andy} } @article {KNZ001927, title = {Mean annual precipitation predicts primary production resistance and resilience to extreme drought}, journal = {Science of The Total Environment}, volume = {636}, year = {2018}, pages = {360 - 366}, abstract = {

Extreme drought is increasing in frequency and intensity in many regions globally, with uncertain consequences for the resistance and resilience of ecosystem functions, including primary production. Primary production resistance, the capacity to withstand change during extreme drought, and resilience, the degree to which production recovers, vary among and within ecosystem types, obscuring generalized patterns of ecological stability. Theory and many observations suggest forest production is more resistant but less resilient than grassland production to extreme drought; however, studies of production sensitivity to precipitation variability indicate that the processes controlling resistance and resilience may be influenced more by mean annual precipitation (MAP) than ecosystem type. Here, we conducted a global meta-analysis to investigate primary production resistance and resilience to extreme drought in 64 forests and grasslands across a broad MAP gradient. We found resistance to extreme drought was predicted by MAP; however, grasslands (positive) and forests (negative) exhibited opposing resilience relationships with MAP. Our findings indicate that common plant physiological mechanisms may determine grassland and forest resistance to extreme drought, whereas differences among plant residents in turnover time, plant architecture, and drought adaptive strategies likely underlie divergent resilience patterns. The low resistance and resilience of dry grasslands suggests that these ecosystems are the most vulnerable to extreme drought \– a vulnerability that is expected to compound as extreme drought frequency increases in the future.

}, keywords = {LTER-KNZ}, doi = {10.1016/j.scitotenv.2018.04.290}, url = {https://doi.org/10.1016/j.scitotenv.2018.04.290}, author = {Ha{\"e}ntjens, Ellen and De Boeck, Hans J. and Lemoine, Nathan P. and M{\"a}nd, Pille and Dulay, K.G. and Schmidt, Inger K. and Jentsch, Anke and Stampfli, Andreas and Anderegg, William R.L. and Michael Bahn and Kreyling, Juergen and Wohlgemuth, Thomas and Lloret, Francisco and Classen, T.Aim{\'e}e. and Gough, Christopher M. and M.D. Smith} } @article {KNZ001902, title = {Mycorrhizal symbioses influence the trophic structure of the Serengeti}, journal = {Journal of Ecology}, volume = {106}, year = {2018}, pages = {536 - 546}, abstract = {
  2. To do this, we first measured the neutral lipid fatty acid biomarker 16:1ω5 to estimate the biomass of AM fungi in a long-term grazing exclusion experiment. Then, we used model selection of Bayesian linear regressions to infer the primary factors that influence AM fungal biomass. Using model selection of different combinations of soil characteristics, we selected the best model using the leave-one-out cross-validation information criterion. Finally, we used the Madingley model to simulate the influence of AM fungi on higher trophic levels. We combined spatially explicit information about soil phosphorus and AM fungal biomass to explore the emergent patterns of the Serengeti resulting from AM symbioses.
  4. Synthesis. Our analysis shows that inputs of phosphorus through arbuscular mycorrhizal symbioses substantially increase the ability of plants to grow and maintain nutritional quality, cascading through the biomass of consumers and predators in the ecosystem. Although they account for less than 1\% of the total modelled biomass, the predicted nutritional benefit provided by arbuscular mycorrhizal fungi increased the biomass of macro-organisms in the Serengeti by 48\%. When considering the management of biodiversity, future ecosystem models should account for the influence of arbuscular mycorrhizal fungi on all trophic levels.

}, keywords = {LTER-KNZ}, doi = {10.1111/1365-2745.12916}, url = {http://doi.wiley.com/10.1111/1365-2745.12916}, author = {Stevens, Bo Maxwell and Propster, Jeffrey and G.T. Wilson and Abraham, Andrew and Ridenour, Chase and Doughty, Christopher and Johnson, Nancy Collins}, editor = {Wurzburger, Nina} } @article {KNZ001822, title = {Partitioning assimilatory nitrogen uptake in streams: an analysis of stable isotope tracer additions across continents}, journal = {Ecological Monographs}, volume = {88}, year = {2018}, pages = {138}, chapter = {120}, abstract = {


}, keywords = {LTER-KNZ}, doi = {10.1002/ecm.1280}, url = {https://esajournals.onlinelibrary.wiley.com/doi/full/10.1002/ecm.1280}, author = {Tank, J.L. and Marti, E. and Riis, T. and von Schiller, D. and Reisinger, A.J. and W. K. Dodds and M.R. Whiles and L.R. Ashkenas and W.B. Bowden and S. M. Collins and Crenshaw, C.L. and Crowl, T.A. and Griffiths, N.A. and Grimm, N.B. and Hamilton, S.K. and Johnson, S.L. and McDowell, W.H. and Norman, B.M. and Rosi, E.J. and Simon, K.S. and Thomas, S.A. and Webster, J.R.} } @article {KNZ001864, title = {Similarity of stream width distributions across headwater systems}, journal = {Nature Communications}, volume = {9}, year = {2018}, chapter = {610}, abstract = {

The morphology and abundance of streams control the rates of hydraulic and biogeochemical exchange between streams, groundwater, and the atmosphere. In large river systems, the relationship between river width and abundance is fractal, such that narrow rivers are proportionally more common than wider rivers. However, in headwater systems, where many biogeochemical reactions are most rapid, the relationship between stream width and abundance is unknown. To constrain this uncertainty, we surveyed stream hydromorphology (wetted width and length) in several headwater stream networks across North America and New Zealand. Here, we find a strikingly consistent lognormal statistical distribution of stream width, including a characteristic most abundant stream width of 32\ \±\ 7\ cm independent of discharge or physiographic conditions. We propose a hydromorphic model that can be used to more accurately estimate the hydromorphology of streams, with significant impact on the understanding of the hydraulic, ecological, and biogeochemical functions of stream networks.

}, keywords = {LTER-KNZ}, doi = {10.1038/s41467-018-02991-w}, url = {https://www.nature.com/articles/s41467-018-02991-w}, author = {Allen, George H. and Pavelsky, Tamlin M. and Barefoot, Eric A. and Lamb, Michael P. and Butman, David and Tashie, Arik and Gleason, Colin J.} } @article {KNZ001882, title = {Spatial heterogeneity in species composition constrains plant community responses to herbivory and fertilisation}, journal = {Ecology Letters}, volume = {21}, year = {2018}, pages = {1364 -1371}, abstract = {


}, keywords = {LTER-KNZ}, doi = {10.1111/ele.13102}, url = {https://onlinelibrary.wiley.com/doi/pdf/10.1111/ele.13102}, author = {Hodapp, Dorothee and E.T. Borer and Harpole, W. Stanley and Lind, Eric M. and Seabloom, Eric W. and P. Adler and J. Alberti and Arnillas, Carlos A. and J.D. Bakker and L.A. Biederman and Cadotte, Marc and Cleland, Elsa E. and Scott. L. Collins and Fay, Philip A. and Firn, Jennifer and Hagenah, Nicole and Hautier, Yann and Iribarne, Oscar and Knops, Johannes M. H. and McCulley, Rebecca L. and MacDougall, Andrew and Joslin L. Moore and J.W. Morgan and Mortensen, Brent and Kimberly J. La Pierre and Risch, Anita C. and Sch{\"u}tz, Martin and Peri, Pablo and Stevens, Carly J. and Wright, Justin and Hillebrand, Helmut}, editor = {Gurevitch, Jessica} } @article {KNZ001742, title = {Analysis and estimation of tallgrass prairie evapotranspiration in the central United States}, journal = {Agricultural and Forest Meteorology}, volume = {232}, year = {2017}, pages = {35-47}, abstract = {

Understanding the factors controlling evapotranspiration (ET) of spatially distributed tallgrass prairie is crucial to accurately upscale ET and to predict the response of tallgrass prairie ecosystems to current and future climate. The Moderate Resolution Imaging Spectroradiometer (MODIS)-derived enhanced vegetation index (EVI) and ground-based climate variables were integrated with eddy covariance tower-based ET (ETEC) at six AmeriFlux tallgrass prairie sites in the central United States to determine major climatic factors that control ET over multiple timescales and to develop a simple and robust statistical model for predicting ET. Variability in ET was nearly identical across sites over a range of timescales, and it was most strongly driven by photosynthetically active radiation (PAR) at hourly-to-weekly timescales, by vapor pressure deficit (VPD) at weekly-to-monthly timescales, and by temperature at seasonal-to-interannual timescales at all sites. Thus, the climatic drivers of ET change over multiple timescales. The EVI tracked the seasonal variation of ETEC well at both individual sites (R2\ \>\ 0.70) and across six sites (R2\ =\ 0.76). The inclusion of PAR further improved the ET-EVI relationship (R2\ =\ 0.86). Based on this result, we used ETEC, EVI, and PAR (MJ\ m\−2 d\−1) data from four sites (15 site-years) to develop a statistical model (ET\ =\ 0.11 PAR\ +\ 5.49 EVI \− 1.43, adj. R2\ =\ 0.86, P\ \<\ 0.0001) for predicting daily ET at 8-day intervals. This predictive model was evaluated against additional two years of ETEC data from one of the four model development sites and two independent sites. The predicted ET (ETEVI+PAR) captured the seasonal patterns and magnitudes of ETEC, and correlated well with ETEC, with R2 of 0.87-0.96 and RMSE of 0.35-0.49\ mm\ d\−1, and it was significantly improved compared to the standard MODIS ET product. This study demonstrated that tallgrass prairie ET can be accurately predicted using a multiple regression model that uses EVI and PAR which can be readily derived from remote sensing data.

}, keywords = {LTER-KNZ, Artificial neural network, Eddy covariance, Empirical model, ET modeling, remote sensing, Wavelet cross-correlation analysis}, doi = {10.1016/j.agrformet.2016.08.005}, url = {https://www.sciencedirect.com/science/article/pii/S0168192316303604?via\%3Dihub}, author = {Wagle, P. and Xiao, X. and Gowda, P. and Basara, J. and N. Brunsell and Steiner, J. and Anup, K.C.} } @article {KNZ001842, title = {Asynchrony among local communities stabilises ecosystem function of metacommunities}, journal = {Ecology Letters}, year = {2017}, abstract = {



Studies of trophic-level material and energy transfers are central to ecology.\ The use of isotopic tracers has now made it possible to measure trophic transfer efficiencies of important nutrients and to better understand how these materials move through food webs.\ We analyzed data from thirteen\ 15N-ammonium tracer addition experiments to quantify N transfer from basal resources to animals in headwater streams with varying physical, chemical, and biological features. N transfer efficiencies from primary uptake compartments (PUCs; heterotrophic microorganisms and primary producers) to primary consumers was lower (mean 11.5\%, range \<1\% to 43\%) than N transfer efficiencies from primary consumers to predators (mean 80\%, range 5\% to \>100\%). Total N transferred (as a rate) was greater in streams with open compared to closed canopies and overall N transfer efficiency generally followed a similar pattern, although was not statistically significant. We used principal component analysis to condense a suite of site characteristics into two environmental components. Total N uptake rates among trophic levels were best predicted by the component that was correlated with latitude, DIN:SRP, GPP:ER, and percent canopy cover. N transfer efficiency did not respond consistently to environmental variables. Our results suggest that canopy cover influences N movement through stream food webs because light availability and primary production facilitate N transfer to higher trophic levels.

}, keywords = {LTER-KNZ}, doi = {10.1002/ecy.2009}, url = {https://esajournals.onlinelibrary.wiley.com/doi/abs/10.1002/ecy.2009}, author = {Norman, B. C. and Whiles, M. R. and S. M. Collins and Flecker, A. S. and Hamilton, S. K. and Johnson, S. L. and Rosi-Marshall, E. J. and L.R. Ashkenas and W.B. Bowden and Crenshaw, C. L. and Crowl, T. and W. K. Dodds and Hall, R. O. and El-Sabaawi, R. and Griffiths, N. A. and Marti, E. and McDowell, W. H. and Peterson, S. D. and Rantala, H. M. and Riis, T. and Simon, K. S. and Tank, J. L. and Thomas, S. A. and von Schiller, D. and Webster, J. R.} } @article {KNZ001810, title = {Global synthesis of the temperature sensitivity of leaf litter breakdown in streams and rivers}, journal = {Global Change Biology}, volume = {23}, year = {2017}, pages = {3064-3075}, abstract = {

Streams and rivers are important conduits of terrestrially derived carbon (C) to atmospheric and marine reservoirs. Leaf litter breakdown rates are expected to increase as water temperatures rise in response to climate change. The magnitude of increase in breakdown rates is uncertain, given differences in litter quality and microbial and detritivore community responses to temperature, factors that can influence the apparent temperature sensitivity of breakdown and the relative proportion of C lost to the atmosphere vs. stored or transported downstream. Here, we synthesized 1025 records of litter breakdown in streams and rivers to quantify its temperature sensitivity, as measured by the activation energy (Ea, in eV). Temperature sensitivity of litter breakdown varied among twelve plant genera for which Ea could be calculated. Higher values of Ea were correlated with lower-quality litter, but these correlations were influenced by a single, N-fixing genus (Alnus). Ea values converged when genera were classified into three breakdown rate categories, potentially due to continual water availability in streams and rivers modulating the influence of leaf chemistry on breakdown. Across all data representing 85 plant genera, the Ea was 0.34 \± 0.04 eV, or approximately half the value (0.65 eV) predicted by metabolic theory. Our results indicate that average breakdown rates may increase by 5\–21\% with a 1\–4 \°C rise in water temperature, rather than a 10\–45\% increase expected, according to metabolic theory. Differential warming of tropical and temperate biomes could result in a similar proportional increase in breakdown rates, despite variation in Ea values for these regions (0.75 \± 0.13 eV and 0.27 \± 0.05 eV, respectively). The relative proportions of gaseous C loss and organic matter transport downstream should not change with rising temperature given that Ea values for breakdown mediated by microbes alone and microbes plus detritivores were similar at the global scale.

}, keywords = {LTER-KNZ}, doi = {10.1111/gcb.13609}, url = {https://onlinelibrary.wiley.com/doi/abs/10.1111/gcb.13609}, author = {Follstad-Shah, J.J. and Kominoski, John S. and Ard{\'o}n, Marcelo and W. K. Dodds and Gessner, Mark O. and Griffiths, Natalie A. and Hawkins, Charles P. and Johnson, Sherri L. and Lecerf, Antoine and LeRoy, Carri J. and Manning, David W. P. and Rosemond, Amy D. and Sinsabaugh, Robert L. and Swan, Christopher M. and Webster, Jackson R. and Lydia H. Zeglin} } @article {KNZ001895, title = {Increased grassland arthropod production with mammalian herbivory and eutrophication: a test of mediation pathways}, journal = {Ecology}, volume = {98}, year = {2017}, pages = {3022-3033}, abstract = {

Increases in nutrient availability and alterations to mammalian herbivore communities are a hallmark of the Anthropocene, with consequences for the primary producer communities in many ecosystems. While progress has advanced understanding of plant community responses to these perturbations, the consequences for energy flow to higher trophic levels in the form of secondary production are less well understood. We quantified arthropod biomass after manipulating soil nutrient availability and wild mammalian herbivory, using identical methods across 13 temperate grasslands. Of experimental increases in nitrogen, phosphorus, and potassium, only treatments including nitrogen resulted in significantly increased arthropod biomass. Wild mammalian herbivore removal had a marginal, negative effect on arthropod biomass, with no interaction with nutrient availability. Path analysis including all sites implicated nutrient content of the primary producers as a driver of increased arthropod mean size, which we confirmed using 10 sites for which we had foliar nutrient data. Plant biomass and physical structure mediated the increase in arthropod abundance, while the nitrogen treatments accounted for additional variation not explained by our measured plant variables. The mean size of arthropod individuals was 2.5 times more influential on the plot-level total arthropod biomass than was the number of individuals. The eutrophication of grasslands through human activity, especially nitrogen deposition, thus may contribute to higher production of arthropod consumers through increases in nutrient availability across trophic levels.

}, keywords = {LTER-KNZ}, doi = {10.1002/ecy.2029}, url = {http://doi.wiley.com/10.1002/ecy.2029}, author = {Lind, Eric M. and Kimberly J. La Pierre and Seabloom, Eric W. and J. Alberti and Iribarne, Oscar and Firn, Jennifer and Gruner, Daniel S. and Kay, Adam D. and Pascal, Jesus and Wright, Justin P. and Yang, Louie and E.T. Borer} } @article {KNZ001803, title = {A long-term study of burning effects on a plant pathogen in tallgrass prairie}, journal = {Plant Pathology}, volume = {66}, year = {2017}, pages = {1308{\textendash}1317}, abstract = {Tallgrass prairie species have evolved with regular exposure to fire. Yet burning has been used as a management tool for reducing plant disease in agricultural systems, posing the question of how plant pathogens of tallgrass prairie will be affected by burning. We studied the rust fungus Puccinia dioicae infecting Erigeron strigosus (Asteraceae) for eight years in long-term experiments to evaluate burning effects in native tallgrass prairie. This experiment also allowed evaluation of the effects of nutrient additions, although E. strigosus was rare in the nutrient addition plots in most years. Burning reduced rust severity in most years. Effects of nutrient additions were rarely observed. There was high inter-annual variation in rust severity within a location, suggesting that weather may be the most important of these three abiotic factors in determining infection. An analysis of weather variables associated with disease severity found that solar radiation in the month prior to sampling was associated with severity in unburned plots; temperature approximately two months prior to sampling was associated with severity in burned plots. High inter-annual variation also suggests that the effects of this pathogen on its host would be sporadic and difficult to study in short-term experiments.}, keywords = {LTER-KNZ}, doi = {10.1111/ppa.12678}, url = {https://esajournals.onlinelibrary.wiley.com/doi/abs/10.1002/ecm.1249}, author = {Dendy, S. P. and Tong, B. and Alexander, H. A. and Fay, P. A. and Murray, L. and Xing, Y. and Garrett, K. A.} } @phdthesis {KNZ001861, title = {Nonreproductive ecology of a nearctic-neotropical migratory bird in the managed rangelands of northern Uruguay}, volume = {PhD Dissertation}, year = {2017}, school = {Universidad de la Rep{\'u}blica in Montevideo}, type = {Ph.D. Thesis}, address = {Montevideo, Uruguay}, keywords = {LTER-KNZ}, author = {M. Alfaro-Barrios} } @article {KNZ001872, title = {Novel observations of larval fire survival, feeding behavior, and host plant use in the regal fritillary, speyeria idalia (Drury) (Nymphalidae)}, journal = {Journal of the Lepidopterists{\textquoteright} Society}, volume = {71}, year = {2017}, pages = {146 - 152}, abstract = {

Speyeria idalia is a prairie specialist that has experienced dramatic population declines throughout its range. Speyeria idalia is nearly extirpated from the eastern portion of its former range; however, populations within Kansas are relatively stable. We made several previously undescribed field observations of late-instar larvae and post-diapause female S. idalia in northeastern Kansas during 2014\–2016. We report finding late-instar larvae at locations that were burned within weeks of detection. The observations of larvae shortly following a burn suggests that S. idalia larvae are capable of surviving fire and contradicts our current knowledge of this species. Additionally, we describe a feeding behavior characteristic of late-instar larvae. Larvae observed in the field and lab stripped leaves of host plants leaving only stems. This strip-style feeding behavior provided unique feeding evidence that was valuable to detecting the presence of larvae in the field. Finally, we documented larvae and post-diapause, egg depositing females using Viola sororia. The use of this relatively widespread and common plant by S. idalia populations in the Central Great Plains has only been implicitly documented but may have important conservation implications. These novel observations further our knowledge of the ecology of this imperiled species and provide timely information that may improve research and conservation management efforts directed toward S. idalia populations.

}, keywords = {LTER-KNZ, conservation, feeding sign, Grasslands, Great Plains, violet}, doi = {10.18473/lepi.71i3.a4}, url = {https://doi.org/10.18473/lepi.71i3.a4}, author = {McCullough, Kelsey and Gene Albanese and David A. Haukos} } @article {KNZ001893, title = {Out of the shadows: multiple nutrient limitations drive relationships among biomass, light and plant diversity}, journal = {Functional Ecology}, volume = {31}, year = {2017}, pages = {1839-1846}, abstract = {
  1. The paradigmatic hypothesis for the effect of fertilisation on plant diversity represents a one-dimensional trade-off for plants competing for below-ground nutrients (generically) and above-ground light: fertilisation reduces competition for nutrients while increasing biomass and thereby shifts competition for depleted available light.
  4. We disagree with DeMalach and Kadmon that light is the \‘main\’ factor explaining diversity, because this misrepresents the causal structure represented in the design of our experiment in which multiple nutrient addition was the ultimate causal driver of a suite of correlated responses that included diversity and light, and especially live and dead biomass, which are the factors that control light depletion.
  5. Our findings highlight that multiple nutrient limitations can structure plant diversity and composition independently of changes in light and biomass. For example, approximately one-third of our sites showed no significant increase in biomass with greater number of added nutrients yet still lost diversity when nutrients were added.
}, keywords = {LTER-KNZ}, doi = {10.1111/1365-2435.12967}, url = {https://besjournals.onlinelibrary.wiley.com/doi/abs/10.1111/1365-2435.12967}, author = {Harpole, W. Stanley and L.L. Sullivan and Lind, Eric M. and Firn, Jennifer and P. Adler and E.T. Borer and Chase, Jonathan and Fay, Philip A. and Hautier, Yann and Hillebrand, Helmut and MacDougall, Andrew S. and Seabloom, Eric W. and Bakker, Jonathan D. and Cadotte, Marc W. and Chaneton, Enrique J. and Chu, Chengjin and Hagenah, Nicole and Kirkman, Kevin and Kimberly J. La Pierre and Joslin L. Moore and J.W. Morgan and Prober, Suzanne M. and Risch, Anita C. and Schuetz, Martin and Stevens, Carly J.}, editor = {Thompson, Ken} } @mastersthesis {KNZ001859, title = {Partitioning the CO2 net flux into assimilation and respiration components, and estimating water use efficiency in a grassland ecosystem}, volume = {MS Thesis}, year = {2017}, school = {Federal University of Vicosa}, type = {M.S. Thesis}, address = {Vi{\c c}osa, Brazil}, keywords = {LTER-KNZ}, author = {Alves, J.D.N.} } @article {KNZ001854, title = {Phenotypic distribution models corroborate species distribution models: A shift in the role and prevalence of a dominant prairie grass in response to climate change}, journal = {Global Change Biology}, volume = {23}, year = {2017}, pages = {4365{\textendash}4375}, abstract = {


}, keywords = {LTER-KNZ}, doi = {10.1111/gcb.13666}, url = {https://onlinelibrary.wiley.com/doi/abs/10.1111/gcb.13666}, author = {Smith, A.B. and Alsdurf, J. and Knapp, M. and S.G. Baer and Johnson, L.C.} } @article {KNZ001783, title = {Pushing precipitation to the extremes in distributed experiments: recommendations for simulating wet and dry years}, journal = {Global Change Biology}, volume = {23}, year = {2017}, pages = {1774-1782}, abstract = {


}, keywords = {LTER-KNZ}, doi = {10.1111/gcb.13504}, url = {https://onlinelibrary.wiley.com/doi/abs/10.1111/gcb.13504}, author = {Alan K. Knapp and M.L. Avolio and Beier, C. and Carroll, C.J.W. and Scott. L. Collins and Dukes, J.S. and Fraser, L.H. and Griffin-Nolan, R.J. and Hoover, D.L. and Jentsch, A. and Loik, M.E. and Phillips, R.P. and Post, A.K. and Sala, O.E. and Slette, I.J. and Yahdjian, L. and M.D. Smith} } @mastersthesis {KNZ001816, title = {The role of soil heterogeneity in the recruitment of new species and interactions with grasshoppers (Acrididae) and Katydids (Tettigoniidae) in restored prairie}, volume = {MS Thesis}, year = {2017}, school = {Southern Illinois University}, type = {M.S. Thesis}, address = {Carbondale, IL}, keywords = {LTER-KNZ}, url = {https://opensiuc.lib.siu.edu/theses/2080/}, author = {T. Adams} } @article {KNZ001755, title = {Addition of multiple limiting resources reduces grassland diversity}, journal = {Nature}, volume = {537}, year = {2016}, pages = {93-96}, abstract = {


}, keywords = {LTER-KNZ}, doi = {10.1038/nature19324}, url = {https://www.nature.com/articles/nature19324}, author = {Harpole, W. S. and L.L. Sullivan and Lind, E.M. and Firn, J. and P. Adler and E.T. Borer and Chase, J. and Fay, P.A. and Hautier, Y. and Hillebrand, H. and MacDougall, A.S. and Seabloom, E.W. and Williams, R. and J.D. Bakker and Cadotte, M.W. and Chaneton, E.J. and Chu, C. and Cleland, E.E. and Antonio, C. and Davies, K.F. and Gruner, D.S. and Hagenah, N. and Kirkman, K. and Knops, J.M.H. and Kimberly J. La Pierre and McCulley, R.L. and Joslin L. Moore and J.W. Morgan and Prober, S.M. and A. Risch and Schuetz, M. and Stevens, C.J. and Wragg, P.D.} } @article {KNZ001707, title = {Bison and cattle grazing management, bare ground coverage, and links to suspended sediment concentrations in grassland streams}, journal = {Journal of the American Water Resources Association}, volume = {52}, year = {2016}, pages = {16-30}, abstract = {

This study quantified the impact of bison and cattle grazing management practices on bare ground coverage at the watershed, riparian, and forested riparian scales within the Flint Hills ecoregion in Kansas. We tested for correlations between bare ground coverage and fluvial suspended sediment concentrations during base-flow and storm-flow events. We used remotely sensed imagery combined with field surveys to classify ground cover and quantify the presence of bare ground. Base-flow water samples were collected bi-monthly during rain-free periods and 24 h following precipitation events. Storm-flow water samples were collected on the rising limb of the hydrograph, using single-stage automatic samplers. Ungrazed treatments contained the lowest coverage of bare ground at the watershed, riparian, and forested riparian scales. Bison treatments contained the highest coverage of bare ground at the watershed scale, while high-density cattle treatments contained the highest coverage of bare ground at the riparian and forested riparian scales. In bison and cattle-grazed treatments, a majority of bare ground was located near fence lines, watershed boundaries, and third- and fourth-order stream segments. Inorganic sediment concentrations at base flow were best predicted by riparian bare ground coverage, while storm-flow sediment concentrations were best predicted by watershed scale bare ground coverage.

}, keywords = {LTER-KNZ}, doi = {10.1111/1752-1688.12364}, url = {https://onlinelibrary.wiley.com/doi/abs/10.1111/1752-1688.12364}, author = {Grudzinski, B.P. and Daniels, M.D. and Anibas, K. and Spencer, D.} } @article {KNZ002022, title = {Changes in spatial and temporal trends in wet, dry, warm and cold spell length or duration indices in Kansas, USA}, journal = {International Journal of Climatology}, volume = {36}, year = {2016}, pages = {4085 - 4101}, keywords = {LTER-KNZ}, doi = {10.1002/joc.4619}, url = {http://doi.wiley.com/10.1002/joc.4619}, author = {Anandhi, Aavudai and Hutchinson, Stacy and Harrington, John and Rahmani, Vahid and Kirkham, Mary B. and C. W. Rice} } @article {KNZ001747, title = {Climate modifies response of non-native and native species richness to nutrient enrichment}, journal = {Philosophical Transactions of the Royal Society B: Biological Sciences}, volume = {3719371}, year = {2016}, pages = {20150273}, abstract = {


}, keywords = {LTER-KNZ}, issn = {0962-8436}, doi = {10.1098/rstb.2015.0273}, url = {https://royalsocietypublishing.org/doi/10.1098/rstb.2015.0273}, author = {Flores-Moreno, H. and P.B. Reich and Lind, E.M. and L.L. Sullivan and Seabloom, E.W. and Yahdjian, L. and MacDougall, A.S. and Reichmann, L.G. and J. Alberti and B{\'a}ez, S. and J.D. Bakker and Cadotte, M.W. and Caldeira, M.C. and Chaneton, E.J. and D{\textquoteright}Antonio, C.M. and Fay, P.A. and Firn, J. and Hagenah, N. and Harpole, W. S. and Iribarne, O. and Kirkman, K.P. and Knops, J.M. H. and Kimberly J. La Pierre and Laungani, R. and Leakey, A.D. B. and McCulley, R.L. and Joslin L. Moore and Pascual, J. and E.T. Borer} } @article {KNZ001869, title = {Gene expression patterns of two dominant tallgrass prairie species differ in response to warming and altered precipitation}, journal = {Scientific Reports}, volume = {6}, year = {2016}, pages = {25522}, abstract = {


}, keywords = {LTER-KNZ}, doi = {10.1038/srep25522}, url = {https://www.nature.com/articles/srep25522}, author = {M.D. Smith and Hoffman, A.M. and M.L. Avolio} } @article {KNZ001787, title = {Integrative modelling reveals mechanisms linking productivity and plant species richness}, journal = {Nature}, volume = {529}, year = {2016}, pages = {390 - 393}, abstract = {


}, keywords = {LTER-KNZ}, doi = {10.1038/nature16524}, url = {https://www.nature.com/articles/nature16524}, author = {Grace, J.B. and Anderson, T.M. and Seabloom, E.W. and E.T. Borer and P. Adler and Harpole, W.S. and Hautier, Y. and Hillebrand, H. and Lind, E.M. and P{\"a}rtel, M. and J.D. Bakker and Buckley, Y.M. and Crawley, M.J. and Damschen, E.I. and Davies, K.F. and Fay, P.A. and Firn, J. and Gruner, D.S. and Hector, A. and Knops, J.M.H. and MacDougall, A.S. and Melbourne, B.A. and J.W. Morgan and Orrock, J.L. and Prober, S.M. and M.D. Smith} } @article {KNZ001733, title = {Nutrient additions cause divergence of tallgrass prairie plant communities resulting in loss of ecosystem stability}, journal = {Journal of Ecology}, volume = {104}, year = {2016}, pages = {1478-1487}, abstract = {


}, keywords = {LTER-KNZ}, doi = {10.1111/1365-2745.12610}, url = {https://besjournals.onlinelibrary.wiley.com/doi/full/10.1111/1365-2745.12610}, author = {Koerner, S.E. and M.L. Avolio and Kimberly J. La Pierre and K.R. Wilcox and M.D. Smith and Scott. L. Collins} } @article {KNZ001798, title = {Quantifying global soil carbon losses in response to warming}, journal = {Nature}, volume = {540}, year = {2016}, pages = {104 - 108}, abstract = {

The majority of the Earth\’s terrestrial carbon is stored in the soil. If anthropogenic warming stimulates the loss of this carbon to the atmosphere, it could drive further planetary warming, Despite evidence that warming enhances carbon fluxes to and from the soil, the net global balance between these responses remains uncertain. Here we present a comprehensive analysis of warming-induced changes in soil carbon stocks by assembling data from 49 field experiments located across North America, Europe and Asia. We find that the effects of warming are contingent on the size of the initial soil carbon stock, with considerable losses occurring in high-latitude areas. By extrapolating this empirical relationship to the global scale, we provide estimates of soil carbon sensitivity to warming that may help to constrain Earth system model projections. Our empirical relationship suggests that global soil carbon stocks in the upper soil horizons will fall by 30\ \±\ 30 petagrams of carbon to 203\ \±\ 161 petagrams of carbon under one degree of warming, depending on the rate at which the effects of warming are realized. Under the conservative assumption that the response of soil carbon to warming occurs within a year, a business-as-usual climate scenario would drive the loss of 55\ \±\ 50 petagrams of carbon from the upper soil horizons by 2050. This value is around 12\–17 per cent of the expected anthropogenic emissions over this period. Despite the considerable uncertainty in our estimates, the direction of the global soil carbon response is consistent across all scenarios. This provides strong empirical support for the idea that rising temperatures will stimulate the net loss of soil carbon to the atmosphere, driving a positive land carbon\–climate feedback that could accelerate climate change.

}, keywords = {LTER-KNZ, Biogeochemistry, carbon cycle}, doi = {10.1038/nature20150}, url = {https://www.nature.com/articles/nature20150}, author = {Crowther, T. W. and Todd-Brown, K. E. O. and Rowe, C. W. and Wieder, W. R. and Carey, J. C. and Machmuller, M. B. and Snoek, B. L. and Fang, S. and Zhou, G. and Allison, S. D. and John M. Blair and Bridgham, S. D. and Burton, A. J. and Carrillo, Y. and Reich, P. B. and Clark, J. S. and Classen, A. T. and Dijkstra, F. A. and Elberling, B. and Emmett, B. A. and Estiarte, M. and Frey, S. D. and Guo, J. and Harte, J. and Jiang, L. and Johnson, B. R. and Kr{\"o}el-Dulay, G. and Larsen, K. S. and Laudon, H. and Lavallee, J. M. and Luo, Y. and Lupascu, M. and Ma, L. N. and Marhan, S. and Michelsen, A. and Mohan, J. and Niu, S. and Pendall, E. and {\~n}uelas, J. and Pfeifer-Meister, L. and Poll, C. and Reinsch, S. and Reynolds, L. L. and Schmidt, I. K. and Sistla, S. and Sokol, N. W. and Templer, P. H. and Treseder, K. K. and Welker, J. M. and Bradford, M. A.} } @article {KNZ001684, title = {Characterizing differences in precipitation regimes of extreme wet and dry years: Implications for climate change experiments}, journal = {Global Change Biology}, volume = {21}, year = {2015}, pages = {2624 -2633}, abstract = {


}, keywords = {LTER-KNZ, rainfall patterns}, doi = {10.1111/gcb.12888}, url = {https://onlinelibrary.wiley.com/doi/abs/10.1111/gcb.12888}, author = {Alan K. Knapp and D.L. Hoover and K.R. Wilcox and M.L. Avolio and Koerner, S.E. and Kimberly J. La Pierre and Loik, M.E. and Luo, Y. and Sala, O.E. and M.D. Smith} } @article {KNZ001717, title = {The diet of upland sandpipers (Bartramia longicauda) in managed farmland in their neotropical non-breeding grounds}, journal = {Ornitolog{\'\i}a Neotropical}, volume = {26}, year = {2015}, pages = {337-347}, abstract = {

The Upland Sandpiper (Bartramia longicauda) is a migratory shorebird that inhabits grasslands at the breeding and non-breeding grounds. The trophic ecology of the species is poorly known, but it is thought to be insectivorous. In this study, we describe the diet of the Upland Sandpiper and its temporal variation in grasslands of northern Uruguay. From 2008 to 2012, we collected 67 feces at nine different sites in the Departments of Salto and Paysand{\'u}. The diet consisted mainly of insects (present in 98\% of the feces) belonging to three orders: Coleoptera (in 80\% of feces), Orthoptera (79\%), and Hymenoptera (48\%). Consumption of Orthoptera and Hymenoptera varied among years. Plant remains and stones were also recorded in feces. Vegetation may have been consumed secondarily while stones could be used in food processing in the gizzard. Our study demonstrates that Upland Sandpipers are diet generalists and probably forage opportunistically, depending on resource availability and focusing on the most abundant prey items.

}, keywords = {LTER-KNZ, Bartramia longicauda; diet; fecal analysis; food preference; grasslands; insects; Nearctic migrant; Scolopacidae; Upland Sandpiper; Uruguay; wintering grounds}, author = {M. Alfaro-Barrios and Sandercock, B.K. and Liguori, L. and Arim, M.} } @article {KNZ001657, title = {The effects of genotype richness and genomic dissimilarity of Andropogon gerardii on invasion resistance and productivity}, journal = {Plant Ecology and Diversity}, volume = {8}, year = {2015}, pages = {61 -71}, abstract = {


}, keywords = {LTER-KNZ, Andropogon bladhii, biodiversity ecosystem function, complementarity, dominant species, genomic dissimilarity, genotypic richness, invasion resistance, productivity, tallgrass prairie}, doi = {10.1080/17550874.2013.866990}, url = {https://www.tandfonline.com/doi/abs/10.1080/17550874.2013.866990}, author = {M.L. Avolio and Chang, C.C. and Weis, J.J. and M.D. Smith} } @article {KNZ001677, title = {Effects of grazing and prescribed fire on resource selection and nest survival of upland sandpipers in an experimental landscape}, journal = {Landscape Ecology}, volume = {30}, year = {2015}, pages = {325 -337}, abstract = {

Context Conservation of grassland vertebrates requires a mechanistic understanding of the effects of landscape heterogeneity on habitat selection and demographic performance. Objectives Our goal was to investigate the effects of rangeland management on resource selection and nest survival of upland sandpipers (Bartramia longicauda). Methods We conducted our project at Konza Prairie, a Long-Term Ecological Research site. The station has 60 experimental units with replicated grazing and fire treatments that create a heterogeneous landscape of different habitat patches. We radio-tracked sandpipers for two breeding seasons (2003\–2004, n = 37 birds) and monitored sandpiper nests for eight seasons (2001\–2008, n = 246 nests). We used resource utilization functions to examine resource selection with respect to five landscape features. Results Home ranges of sandpipers were large in contiguous prairie (x\¯=8.4km2x\¯=8.4km2) and explain area-sensitive occurrence in fragmented prairie. Upland sandpipers selected grazed and burned sites with short vegetation within their home range. In contrast, nest site selection was influenced by fire frequency and birds selected infrequently burned sites with greater vegetative structure. Settlement decisions affected fitness because nest survival was low in burned and grazed sites (0.068), but higher in unburned and ungrazed sites (0.201\–0.247). Conclusions Our results raise concerns for conservation because private rangelands managed for livestock production are often homogeneous landscapes with heavy grazing and frequent fires. Rotational grazing and fire could be used to restore heterogeneity to grasslands but the duration of rotation, patch size, and optimal configuration require further investigation.

}, keywords = {LTER-KNZ, Bartramia longicauda, fire, grassland, Habitat selection, Home range, Landscape heterogeneity, Nest survival, Radio-telemetry, Resource utilization functions, tallgrass prairie}, doi = {10.1007/s10980-014-0133-9}, url = {https://link.springer.com/article/10.1007\%2Fs10980-014-0133-9}, author = {Sandercock, B.K. and M. Alfaro-Barrios and Casey, A.E. and Johnson, T.N. and Mong, T.W. and Odom, K.J. and Strum, K.M. and Winder, V.L.} } @article {KNZ001788, title = {Grassland productivity limited by multiple nutrients}, journal = {Nature Plants}, volume = {1}, year = {2015}, pages = {15080}, abstract = {

Terrestrial ecosystem productivity is widely accepted to be nutrient limited1. Although nitrogen (N) is deemed a key determinant of aboveground net primary production (ANPP)2,3, the prevalence of co-limitation by N and phosphorus (P) is increasingly recognized4,​5,​6,​7,​8. However, the extent to which terrestrial productivity is co-limited by nutrients other than N and P has remained unclear. Here, we report results from a standardized factorial nutrient addition experiment, in which we added N, P and potassium (K) combined with a selection of micronutrients (K+μ), alone or in concert, to 42 grassland sites spanning five continents, and monitored ANPP. Nutrient availability limited productivity at 31 of the 42 grassland sites. And pairwise combinations of N, P, and K+μ co-limited ANPP at 29 of the sites. Nitrogen limitation peaked in cool, high latitude sites. Our findings highlight the importance of less studied nutrients, such as K and micronutrients, for grassland productivity, and point to significant variations in the type and degree of nutrient limitation. We suggest that multiple-nutrient constraints must be considered when assessing the ecosystem-scale consequences of nutrient enrichment.

}, keywords = {LTER-KNZ}, doi = {10.1038/nplants.2015.80}, url = {https://www.nature.com/articles/nplants201580}, author = {Fay, P.A. and Prober, S.M. and Harpole, W.S. and Knops, J.M.H. and J.D. Bakker and E.T. Borer and Lind, E.M. and MacDougall, A.S. and Seabloom, E.W. and Wragg, P.D. and P. Adler and D.M. Blumenthal and Buckley, Y.M. and Chu, C. and Cleland, E.E. and Scott. L. Collins and Davies, K.F. and G. Du and Feng, X. and Firn, J. and Gruner, D.S. and Hagenah, N. and Hautier, Y. and Heckman, R.W. and Jin, V.L. and Kirkman, K.P. and Klein, J. and L. Ladwig and Li, Q. and McCulley, R.L. and Melbourne, B.A. and Mitchell, C.E. and Joslin L. Moore and J.W. Morgan and A. Risch and sch{\"u}tz, M. and Stevens, C.J. and Wedin, D.A. and Yang, L.H.} } @article {KNZ001701, title = {Invasibility of a mesic grassland depends on the time-scale of fluctuating resources}, journal = {Journal of Ecology}, volume = {103}, year = {2015}, pages = {1538 - 1546}, abstract = {


}, keywords = {LTER-KNZ}, doi = {10.1111/1365-2745.12479}, url = {https://besjournals.onlinelibrary.wiley.com/doi/full/10.1111/1365-2745.12479}, author = {Koerner, S.E. and M.L. Avolio and Chang, C.C. and Grey, J. and D.L. Hoover and M.D. Smith} } @article {KNZ001678, title = {Plant diversity predicts beta but not alpha diversity of soil microbes across grasslands worldwide}, journal = {Ecology Letters}, volume = {18}, year = {2015}, pages = {85 -95}, abstract = {

Aboveground\–belowground interactions exert critical controls on the composition and function of terrestrial ecosystems, yet the fundamental relationships between plant diversity and soil microbial diversity remain elusive. Theory predicts predominantly positive associations but tests within single sites have shown variable relationships, and associations between plant and microbial diversity across broad spatial scales remain largely unexplored. We compared the diversity of plant, bacterial, archaeal and fungal communities in one hundred and forty-five 1 m2 plots across 25 temperate grassland sites from four continents. Across sites, the plant alpha diversity patterns were poorly related to those observed for any soil microbial group. However, plant beta diversity (compositional dissimilarity between sites) was significantly correlated with the beta diversity of bacterial and fungal communities, even after controlling for environmental factors. Thus, across a global range of temperate grasslands, plant diversity can predict patterns in the composition of soil microbial communities, but not patterns in alpha diversity.

}, keywords = {LTER-KNZ}, doi = {10.1111/ele.12381}, url = {https://onlinelibrary.wiley.com/doi/abs/10.1111/ele.12381}, author = {Prober, S.M. and Leff, J.W. and Bates, S.T. and E.T. Borer and Firn, J. and Harpole, W.S. and Lind, E.M. and Seabloom, E.W. and P. Adler and J.D. Bakker and E.E Cleland and DeCrappeo, N.M. and DeLorenze, E. and Hagenah, N. and Hautier, Y. and Hofmockel, K.S. and Kirkman, K.P. and Knops, J.M.H. and Kimberly J. La Pierre and MacDougall, A.S. and McCulley, R.L. and Mitchell, C.E. and A. Risch and Schuetz, M. and Stevens, C.J. and Williams, R.J. and Fierer, N.} } @article {KNZ001697, title = {Plant species{\textquoteright} origin predicts dominance and response to nutrient enrichment and herbivores in global grasslands}, journal = {Nature Communications}, volume = {6}, year = {2015}, pages = {7710 -}, abstract = {


}, keywords = {LTER-KNZ, Biological sciences, ecology, Plant sciences}, doi = {10.1038/ncomms8710}, url = {https://www.nature.com/articles/ncomms8710}, author = {Seabloom, E.W. and E.T. Borer and Buckley, Y. and Cleland, E.E. and Davies, K.F. and Firn, J. and Harpole, W.S. and Hautier, Y. and Lind, E. and MacDougall, A.S. and Orrock, J.L. and Prober, S.M. and P. Adler and Anderson, T.M. and J.D. Bakker and L.A. Biederman and D.M. Blumenthal and C.S. Brown and Brudvig, L.A. and Cadotte, M. and Chu, C. and Cottingham, K.L. and Crawley, M.J. and Damschen, E.I. and D{\textquoteright}Antonio, C.M. and CeCrappeo, N.M. and G. Du and Fay, P.A. and Frater, P. and Gruner, D.S. and Hagenah, N. and Hector, A. and Hillebrand, H. and Hofmockel, K.S. and Humphries, H.C. and Jin, V.L. and Kay, A.D. and Kirkman, K.P. and Klein, J.A. and Knops, J.M.H. and Kimberly J. La Pierre and L. Ladwig and Lambrinos, J.G. and Li, Q. and Li, W. and Marushia, R.} } @inbook {KNZ002019, title = {Agriculture, Forestry and Other Land Use (AFOLU)}, booktitle = {Climate Change 2014: Mitigation of Climate Change. Contribution of Working Group III to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change }, year = {2014}, pages = {811-922}, publisher = {Cambridge University Press, Cambridge, United Kingdom and New York, NY, USA.}, organization = {Cambridge University Press, Cambridge, United Kingdom and New York, NY, USA.}, chapter = {11}, keywords = {LTER-KNZ}, url = {https://www.ipcc.ch/report/ar5/wg3/agriculture-forestry-and-other-land-use-afolu/}, author = {Smith, P. and Bustamante, M. and Ahammad, H. and Clark, H. and Dong, H. and Elsiddig, E. A. and Haberl, H. and Harper, R. and J. House and M. Jafari and O. Masera and C. Mbow and N.H. Ravindranath and C. W. Rice and C. Robledo Abad and A. Romanovskaya and F. Sperling and F. Tubiello} } @article {KNZ001792, title = {Anthropogenic-based regional-scale factors most consistently explain plot-level exotic diversity in grasslands}, journal = {Global Ecology and Biogeography}, volume = {23}, year = {2014}, pages = {802 - 810}, abstract = {

Aim Evidence linking the accumulation of exotic species to the suppression of native diversity is equivocal, often relying on data from studies that have used different methods. Plot-level studies often attribute inverse relationships between native and exotic diversity to competition, but regional abiotic filters, including anthropogenic influences, can produce similar patterns. We seek to test these alternatives using identical scale-dependent sampling protocols in multiple grasslands on two continents. Location Thirty-two grassland sites in North America and Australia. Methods We use multiscale observational data, collected identically in grain and extent at each site, to test the association of local and regional factors with the plot-level richness and abundance of native and exotic plants. Sites captured environmental and anthropogenic gradients including land-use intensity, human population density, light and soil resources, climate and elevation. Site selection occurred independently of exotic diversity, meaning that the numbers of exotic species varied randomly thereby reducing potential biases if only highly invaded sites were chosen. Results Regional factors associated directly or indirectly with human activity had the strongest associations with plot-level diversity. These regional drivers had divergent effects: urban-based economic activity was associated with high exotic\ :\ native diversity ratios; climate- and landscape-based indicators of lower human population density were associated with low exotic\ :\ native ratios. Negative correlations between plot-level native and exotic diversity, a potential signature of competitive interactions, were not prevalent; this result did not change along gradients of productivity or heterogeneity. Main conclusion We show that plot-level diversity of native and exotic plants are more consistently associated with regional-scale factors relating to urbanization and climate suitability than measures indicative of competition. These findings clarify the long-standing difficulty in resolving drivers of exotic diversity using single-factor mechanisms, suggesting that multiple interacting anthropogenic-based processes best explain the accumulation of exotic diversity in modern landscapes.

}, keywords = {LTER-KNZ}, doi = {10.1111/geb.12157}, url = {https://onlinelibrary.wiley.com/doi/abs/10.1111/geb.12157}, author = {MacDougall, A.S. and Bennett, J.R. and Firn, J. and Seabloom, E.W. and E.T. Borer and Lind, E.M. and Orrock, J.L. and Harpole, W.S. and Hautier, Y. and P. Adler and Cleland, E. and Davies, K. and Melbourne, B. and Prober, S.M. and J.D. Bakker and Fay, P.A. and Jin, V.L. and Kendig, A. and Kimberly J. La Pierre and Joslin L. Moore and J.W. Morgan and Stevens, C.J.} } @article {KNZ001667, title = {Changes in plant community composition, not diversity, during a decade of nitrogen and phosphorus additions drive above-ground productivity in a tallgrass prairie}, journal = {Journal of Ecology}, volume = {102}, year = {2014}, pages = {1649 -1660}, abstract = {


}, keywords = {LTER-KNZ}, doi = {10.1111/1365-2745.12312}, url = {https://besjournals.onlinelibrary.wiley.com/doi/full/10.1111/1365-2745.12312}, author = {M.L. Avolio and Koerner, S.E. and Kimberly J. La Pierre and K.R. Wilcox and G.T. Wilson and M.D. Smith and Scott. L. Collins} } @article {KNZ001632, title = {Eutrophication weakens stabilizing effects of diversity in natural grasslands}, journal = {Nature}, volume = {508}, year = {2014}, pages = {521 -525}, abstract = {


}, keywords = {LTER-KNZ, Biodiversity, Community ecology, Grassland ecology}, doi = {10.1038/nature13014}, url = {https://www.nature.com/articles/nature13014}, author = {Hautier, Y. and Seabloom, E.W. and E.T. Borer and P. Adler and Harpole, W.S. and Hillebrand, H. and Lind, E.M. and MacDougall, A.S. and Stevens, C.J. and J.D. Bakker and Buckley, Y.M. and Chu, C. and Scott. L. Collins and Daleo, P. and Damschen, E.I. and Davies, K.F. and Fay, P.A. and Firn, J. and Gruner, D.S. and Jin, V.L. and Klein, J.A. and Knops, J.M.H. and Kimberly J. La Pierre and Li, W. and McCulley, R.L. and Melbourne, B.A. and Joslin L. Moore and O{\textquoteright}Halloran, L.R. and Prober, S.M. and A. Risch and Sankaran, M. and Schuetz, M. and Hector, A.} } @article {KNZ001793, title = {Herbivores and nutrients control grassland plant diversity via light limitation}, journal = {Nature}, volume = {508}, year = {2014}, pages = {517 - 520}, keywords = {LTER-KNZ}, doi = {10.1038/nature13144}, url = {https://www.nature.com/articles/nature13144}, author = {E.T. Borer and Seabloom, E.W. and Gruner, D.S. and Harpole, W.S and Hillebrand, H. and Lind, E.M. and P. Adler and J. Alberti and Anderson, T.M. and J.D. Bakker and L.A. Biederman and D.M. Blumenthal and C.S. Brown and Brudvig, L.A. and Buckley, Y.M. and Cadotte, M. and Chu, C. and Cleland, E.E. and Crawley, M.J. and Daleo, P. and Damschen, E.I. and Davies, K.F. and DeCrappeo, N.M. and G. Du and Firn, J. and Hautier, Y. and Heckman, R.W. and Hector, A. and HilleRisLambers, J. and Iribarne, Oscar and Klein, J.A. and Knops, J.M.H. and Kimberly J. La Pierre and Leakey, A.D.B. and Li, W. and MacDougall, A.S. and McCulley, R.L. and Melbourne, B.A. and Mitchell, C.E. and Joslin L. Moore and Mortensen, B. and O{\textquoteright}Halloran, L.R. and Orrock, J.L. and Pascual, J. and Prober, S.M. and Pyke, D.A. and A. Risch and Schuetz, M. and M.D. Smith and Stevens, C.J. and L.L. Sullivan and Williams, R.J. and Wragg, P.D. and Wright, J.P. and Yang, L.H.} } @article {KNZ002020, title = {Knowledge and tools to enhance resilience of beef grazing systems for sustainable animal protein production}, journal = {Annals of the New York Academy of Sciences}, volume = {1328}, year = {2014}, pages = {10 - 17}, keywords = {LTER-KNZ}, doi = {10.1111/nyas.12572}, url = {https://www.ncbi.nlm.nih.gov/pubmed/25376887}, author = {Steiner, Jean L. and Engle, David M. and Xiao, Xiangming and Saleh, Ali and Tomlinson, Peter and C. W. Rice and Cole, N. Andy and Coleman, Samuel W. and Osei, Edward and Basara, Jeffrey and Middendorf, Gerad and Gowda, Prasanna and Todd, Richard and Moffet, Corey and Anandhi, Aavudai and Starks, Patrick J. and Ocshner, Tyson and Reuter, Ryan and Devlin, Daniel} } @article {KNZ001595, title = {Plant-virus interactions and the agro-ecological interface}, journal = {European Journal of Plant Pathology}, volume = {138}, year = {2014}, pages = {529 -537}, abstract = {


}, keywords = {LTER-KNZ, Agro-ecological interface, Crop, Plant fitness, Plant virus, Vector, Wild plant}, doi = {10.1007/s10658-013-0317-1}, url = {https://link.springer.com/article/10.1007\%2Fs10658-013-0317-1}, author = {Alexander, H.M. and Mauck, K.E. and Whitfield, A.E. and Garrett, K.A. and Malmstrom, C.M.} } @article {KNZ001533, title = {Altered precipitation regime affects the function and composition of soil microbial communities on multiple time scales}, journal = {Ecology}, volume = {94}, year = {2013}, pages = {2334 -2345}, abstract = {

Climate change models predict that future precipitation patterns will entail lower-frequency but larger rainfall events, increasing the duration of dry soil conditions. Resulting shifts in microbial C cycling activity could affect soil C storage. Further, microbial response to rainfall events may be constrained by the physiological or nutrient limitation stress of extended drought periods; thus seasonal or multiannual precipitation regimes may influence microbial activity following soil wet-up. We quantified rainfall-driven dynamics of microbial processes that affect soil C loss and retention, and microbial community composition, in soils from a long-term (14-year) field experiment contrasting \“Ambient\” and \“Altered\” (extended intervals between rainfalls) precipitation regimes. We collected soil before, the day following, and five days following 2.5-cm rainfall events during both moist and dry periods (June and September 2011; soil water potential = \−0.01 and \−0.83 MPa, respectively), and measured microbial respiration, microbial biomass, organic matter decomposition potential (extracellular enzyme activities), and microbial community composition (phospholipid fatty acids). The equivalent rainfall events caused equivalent microbial respiration responses in both treatments. In contrast, microbial biomass was higher and increased after rainfall in the Altered treatment soils only, thus microbial C use efficiency (CUE) was higher in Altered than Ambient treatments (0.70 \± 0.03 \> 0.46 \± 0.10). CUE was also higher in dry (September) soils. C-acquiring enzyme activities (β-glucosidase, cellobiohydrolase, and phenol oxidase) increased after rainfall in moist (June), but not dry (September) soils. Both microbial biomass C:N ratios and fungal : bacterial ratios were higher at lower soil water contents, suggesting a functional and/or population-level shift in the microbiota at low soil water contents, and microbial community composition also differed following wet-up and between seasons and treatments. Overall, microbial activity may directly (C respiration) and indirectly (enzyme potential) reduce soil organic matter pools less in drier soils, and soil C sequestration potential (CUE) may be higher in soils with a history of extended dry periods between rainfall events. The implications include that soil C loss may be reduced or compensated for via different mechanisms at varying time scales, and that microbial taxa with better stress tolerance or growth efficiency may be associated with these functional shifts.

}, keywords = {LTER-KNZ}, doi = {10.1890/12-2018.1}, url = {https://esajournals.onlinelibrary.wiley.com/doi/abs/10.1890/12-2018.1}, author = {Lydia H. Zeglin and Bottomley, P.J. and A. Jumpponen and C. W. Rice and Arango, M. and Lindsley, A. and McGowan, A. and Mfombep, P. and Myrold, D.D.} } @article {KNZ001546, title = {Correlations between genetic and species diversity: effects of resource quantity and heterogeneity}, journal = {Journal of Vegetation Science}, volume = {24}, year = {2013}, pages = {1185 -1194}, abstract = {


}, keywords = {LTER-KNZ, Andropogon gerardii, C4 grass, dominant species, grassland, Resource heterogeneity, Resource quantity, Species genetic diversity correlation}, doi = {10.1111/jvs.12042}, url = {https://onlinelibrary.wiley.com/doi/abs/10.1111/jvs.12042}, author = {M.L. Avolio and M.D. Smith} } @article {KNZ001523, title = {Estimating aboveground net primary productivity of the tallgrass prairie ecosystem of the Central Great Plains using AVHRR NDVI}, journal = {International Journal of Remote Sensing}, volume = {34}, year = {2013}, pages = {3717 -3735}, abstract = {

Above-ground net primary productivity (ANPP) is indicative of an ecosystem\&$\#$39;s ability to capture solar energy and convert it to organic carbon (or biomass), which may be used by consumers or decomposers, or stored in the form of living and nonliving organic matter. Annual and interannual variation in ANPP is often linked to climate dynamics and anthropogenic influences, such as fertilization, irrigation, above-ground biomass harvest, and so on. The Central Great Plains grasslands occupy over 1.5 million km2 and are a primary resource for livestock production in North America. The tallgrass prairies are the most productive grasslands in this region, and the Flint Hills of North America represent the largest contiguous area of unploughed tallgrass prairie (1.6 million ha). Measurements of ANPP are of critical importance to the proper management and understanding of climatic and anthropogenic influences on tallgrass prairie. Yet, accurate, detailed, and systematic measurements of ANPP over large geographic regions do not exist for this ecosystem. For these reasons, this study was conducted to investigate the use of the normalized difference vegetation index (NDVI) to model ANPP of the tallgrass prairie. Many studies have established a positive relationship between the NDVI and ANPP, but the strength of this relationship is influenced by vegetation types and can vary significantly from year to year depending on land use and climatic conditions. The goal of this study was to develop a robust model using the Advanced Very High Resolution Radiometer (AVHRR) biweekly NDVI values to predict tallgrass ANPP. This study was conducted using ANPP measurements from a watershed within the Konza Prairie Biological Station (KPBS) as the primary study area, with additional measurements from the Rannells Flint Hills Prairie Preserve (RFHPP) and biennial ANPP measurements by Kansas State University (KSU) students from tallgrass areas near Manhattan, Kansas. Data from the primary study site covered the period of 1989\–2005. The optimal period for estimating ANPP using AVHRR NDVI composite data sets was found to be late July. The Tallgrass ANPP Model (TAM) explained 54\% (coefficient of determination, R 2 = 0.54, p \< 0.001) of the year-to-year variation in ANPP. The creation of 1.0 km \× 1.0 km resolution ANPP maps for a four-county (\∼7000 ha) area for years 1989\–2007 showed considerable variation in annual and interannual ANPP spatial patterns, suggesting complex interactions among factors influencing ANPP spatially and temporally.

}, keywords = {LTER-KNZ}, doi = {10.1080/01431161.2012.757376}, url = {https://doi.org/10.1080/01431161.2012.757376}, author = {An, N. and Price, K.P. and John M. Blair} } @article {KNZ001505, title = {Genetic diversity of a dominant C4 grass is altered with increased precipitation variability}, journal = {Oecologia}, volume = {171}, year = {2013}, pages = {571 -581}, abstract = {


}, keywords = {LTER-KNZ, AFLP, Andropogon gerardii, Dice dissimilarity, dominant species, Genotypic structure}, doi = {10.1007/s00442-012-2427-4}, url = {https://link.springer.com/article/10.1007\%2Fs00442-012-2427-4}, author = {M.L. Avolio and Beaulieu, J. and M.D. Smith} } @article {KNZ002018, title = {Intra-specific responses of a dominant C4 grass to altered precipitation patterns}, journal = {Plant Ecology}, volume = {214}, year = {2013}, pages = {1377 - 1389}, abstract = {

The mechanisms by which global change alters the genotypic structure of populations by selection remain unclear. Key to this understanding is elucidating genotype\–phenotype relationships under different environmental conditions as genotypes could differ in their plasticity or in their tolerance to changing environmental conditions. We have previously observed selection of certain genotypes of the dominant C4 grass Andropogon gerardii L. within the on-going Rainfall Manipulation Plots (RaMPs) experiment at Konza Prairie Biological Station in Kansas. The RaMPs experiment has been experimentally imposing ambient and more variable (altered) precipitation patterns since 1998. Here, we studied phenotypic differences among six genotypes to gain insight into what drove the pattern of selection previously observed and assess potential genotype \× environmental interactions. In 2008 and 2009 we sampled individuals of genotypes in the RaMPs and within unmanipulated reference plots located adjacent to the RaMPs experiment. For each individual, we measured both leaf-level (specific leaf area, stomatal conductance) and whole-plant growth (height, biomass) traits. We consistently detected differences among genotypes in the reference plots. Additionally, when focusing on two genotypes found in the altered and ambient RaMPs we observed no genotype \× environment interactions. Overall, we found in an intact population of A. gerardii there exists phenotypic variability among genotypes, but no genotype \× environment interactions. Thus our results demonstrate that differences in plasticity of genotypes do no explain the pattern of selection we observed.

}, keywords = {LTER-KNZ}, doi = {10.1007/s11258-013-0258-y}, url = {http://link.springer.com/10.1007/s11258-013-0258-y}, author = {M.L. Avolio and M.D. Smith} } @article {KNZ001791, title = {Life-history constraints in grassland plant species: a growth-defence trade-off is the norm}, journal = {Ecology Letters}, volume = {16}, year = {2013}, pages = {513 - 521}, abstract = {

Plant growth can be limited by resource acquisition and defence against consumers, leading to contrasting trade-off possibilities. The competition-defence hypothesis posits a trade-off between competitive ability and defence against enemies (e.g. herbivores and pathogens). The growth-defence hypothesis suggests that strong competitors for nutrients are also defended against enemies, at a cost to growth rate. We tested these hypotheses using observations of 706 plant populations of over 500 species before and following identical fertilisation and fencing treatments at 39 grassland sites worldwide. Strong positive covariance in species responses to both treatments provided support for a growth-defence trade-off: populations that increased with the removal of nutrient limitation (poor competitors) also increased following removal of consumers. This result held globally across 4 years within plant life-history groups and within the majority of individual sites. Thus, a growth-defence trade-off appears to be the norm, and mechanisms maintaining grassland biodiversity may operate within this constraint.

}, keywords = {LTER-KNZ}, doi = {10.1111/ele.12078}, url = {https://onlinelibrary.wiley.com/doi/abs/10.1111/ele.12078}, author = {Lind, E.M. and E.T. Borer and Seabloom, E. and P. Adler and J.D. Bakker and D.M. Blumenthal and Crawley, M. and Davies, K. and Firn, J. and Gruner, D.S. and Harpole, W.S. and Hautier, Y. and Hillebrand, H. and Knops, J. and Melbourne, B. and Mortensen, B. and A. Risch and Schuetz, M. and Stevens, C. and Wragg, P.D.} } @article {KNZ001543, title = {Mechanisms of selection: Phenotypic differences among genotypes explain patterns of selection in a dominant species}, journal = {Ecology}, volume = {94}, year = {2013}, pages = {953 -965}, abstract = {


}, keywords = {LTER-KNZ}, doi = {10.1890/12-1119.1}, url = {https://esajournals.onlinelibrary.wiley.com/doi/abs/10.1890/12-1119.1}, author = {M.L. Avolio and M.D. Smith} } @article {KNZ001790, title = {Predicting invasion in grassland ecosystems: is exotic dominance the real embarrassment of richness?}, journal = {Global Change Biology}, volume = {19}, year = {2013}, pages = {3677 - 3687}, abstract = {


}, keywords = {LTER-KNZ}, doi = {10.1111/gcb.12370}, url = {https://onlinelibrary.wiley.com/doi/abs/10.1111/gcb.12370}, author = {Seabloom, E.W. and E.T. Borer and Buckley, Y. and Cleland, E.E. and Davies, K. and Firn, J. and Harpole, W.S. and Hautier, Y. and Lind, E. and MacDougall, A. and Orrock, J.L. and Prober, S.M. and P. Adler and J. Alberti and Anderson, M.T. and J.D. Bakker and L.A. Biederman and D.M. Blumenthal and C.S. Brown and Brudvig, L.A. and Caldeira, M. and Chu, C. and Crawley, M.J. and Daleo, P. and Damschen, E.I. and D{\textquoteright}Antonio, C.M. and DeCrappeo, N.M. and Dickman, C.R. and G. Du and Fay, P.A. and Frater, P. and Gruner, D.S. and Hagenah, N. and Hector, A. and Helm, A. and Hillebrand, H. and Hofmockel, K.S. and Humphries, H.C. and Iribarne, O. and Jin, V.L. and Kay, A. and Kirkman, K.P. and Klein, J.A. and Knops, J.M.H. and Kimberly J. La Pierre and L. Ladwig and Lambrinos, J.G. and Leakey, A.D.B. and Li, Q. and Li, W. and McCulley, R. and Melbourne, B. and Mitchell, C.E. and Joslin L. Moore and J.W. Morgan and Mortensen, B. and O{\textquoteright}Halloran, L.R. and P{\"a}rtel, M. and Pascual, J and Pyke, D.A. and A. Risch and Salguero-Gomez, R. and Sankaran, M. and Schuetz, M. and Simonsen, A. and M.D. Smith and Stevens, C. and Sullivan, L. and Wardle, G.M. and Wolkovich, E.M. and Wragg, P.D. and Wright, J. and Yang, L.} } @article {KNZ001436, title = {Effects of foundation species genotypic diversity on subordinate species richness in an assembling community}, journal = {Oikos}, volume = {121}, year = {2012}, pages = {496 -507}, abstract = {


}, keywords = {LTER-KNZ}, doi = {10.1111/j.1600-0706.2011.19447.x}, url = {https://onlinelibrary.wiley.com/doi/abs/10.1111/j.1600-0706.2011.19447.x}, author = {D.J. Gibson and Alstadt, A.J. and S.G. Baer and Geisler, M.} } @phdthesis {KNZ001480, title = {Genetic diversity of Andropogon gerardii: Impacts of altered precipitation patterns on a dominant species}, volume = {PhD Dissertation}, year = {2012}, pages = {1 -258}, school = {Yale University}, type = {Ph.D. Thesis}, address = {New Haven, CT}, abstract = {

Global change is expected to shift climatic regimes and cause whole communities of organisms to experience novel environments. Key aspects of forecast climate change are alterations in both the amount of precipitation and the variability of precipitation regimes. The ability of a population to adapt will depend on the genetic diversity of the population, and the traits of the genotypes present in the population. Here, I assess the response a dominant C4 tallgrass population to novel environmental conditions resulting from forecast climate change by studying whether more variable precipitation patterns affect the genetic diversity of Andropogon gerardii. I then investigate the potential mechanisms driving the observed response. Ultimately, the way in which population genetic diversity is affected by more variable precipitation patterns will shed insight into how this important species will adapt to future climate change. First, I developed the tools to study the genetic diversity of A. gerardii at the plant neighborhood scale, the scale at which individuals compete for resources. I designed amplified fragment length polymorphism primers for A. gerardii and determined the appropriate scale at which to sample individuals to accurately capture genetic diversity. I also examined how genetic diversity is measured in ecological studies by comparing genotype-based measures and genome-based measures of diversity. Ultimately, I argue that genome-based measures should be included in future studies alongside genotypic-based measures because they capture a greater spectrum of genetic differences among individuals. Next, using what I established for studying genetic diversity, I examined how a decade of altered precipitation patterns affected the genetic diversity of A. gerardii. To do this I worked within the Rainfall Manipulation Plots (RaMPs) experiment at Konza Prairie Biological Station in Kansas, which experimentally imposes ambient and more variable precipitation patterns. After ten years of experimentally increased intra-annual variability in growing season precipitation regimes, I report that the number of genotypes of the dominant C4 grass, Andropogon gerardii Vitman, has been significantly reduced in native tallgrass prairie compared with unmanipulated prairie. However, individuals showed a different pattern of genomic similarity with increased precipitation variability \– there was greater genome dissimilarity among individuals when compared to unmanipulated prairie. In my next two chapters, I aim to understand the mechanism that drove the observed shift in genetic diversity. First, I studied phenotypic differences among six common genotypes of Andropogon gerardii across three different environmental conditions to study genotype \× environmental interactions. I consistently detected differences among the focal genotypes for all traits measured across environmental treatments, however, I observed no genotype \× year interactions, and phenotypic differences among genotypes were diminished within environmental conditions. To assess potential mechanisms underlying the changes observed in population structure of this species, I continued to study five of the same genotypes, three of which had greater abundances or were only present in plots receiving more variable rainfall patterns. In a greenhouse study, I investigated how both changes in the size and variability of watering events affected ecophysiological, growth, biomass allocation and fitness traits. I found genotype \× water amount interactions for traits related to leaf level physiology and biomass allocation; genotypes that performed better under low soil moisture conditions were outperformed by other genotypes under high soil moisture conditions. For the three genotypes that had greater abundance in plots that received a decade of altered rainfall regimes, I found evidence of phenotypic trait divergence as well as greater plasticity for ecophysiological traits. Lastly, I investigated correlations between species and genetic diversity in tallgrass prairie across an experimental manipulation of soil moisture. I found species and genetic diversity were not correlated, and that genotypic richness was negatively related to soil moisture variability, but measures of species diversity were not related to soil moisture. My results suggest that a lack relationship between species and genetic diversity at the populations scale could be because species and genetic diversity are responding differently to environmental resources. Ultimately, my dissertation is an in-depth examination of how environmental conditions affect the genetic diversity of a dominant species. I found that for genetically diverse species, such as dominant species, microevolution might be an important aspect of adaptation to novel environmental conditions experienced with climate change.

}, keywords = {LTER-KNZ}, url = {http://search.proquest.com/docview/1272028956}, author = {M.L. Avolio} } @inbook {KNZ001478, title = {Insect herbivore outbreaks views through a physiological framework: insights from Orthoptera}, booktitle = {Insect Outbreaks Revisited}, year = {2012}, publisher = {Academic Press, San Diego}, organization = {Academic Press, San Diego}, abstract = {

Insect herbivore outbreaks, particularly orthopteran outbreaks, have plagued humans throughout recorded history. The Egyptian locust swarm described in the Old Testament is perhaps the most famous orthopteran outbreak story. Two species, the African desert locust (Schistocerca gregaria Forsk{\r a}l) and the migratory locust (Locusta migratoria (Linnaeus)), still outbreak regularly throughout large expanses of Africa and the Middle East. The most likely villain in the biblical swarm was the African desert locust, based on the broad array of the food plants described in the story. In contrast to the desert locust, the migratory locust is a specialist that feeds only on grasses. However, despite its restricted diet, the migratory locust has a larger geographic range, extending from all of northern and central Africa across to eastern China. It too has greatly impacted human society throughout historical time, especially in China. Parenthetically, the Chinese character for locust is composed of two parts, insect (虫) and emperor (皇); this character combination indicates the power of locusts \– it was an insect capable of threatening an emperor\’s supremacy. In China\’s 5000-year history, 842 locust plagues have been recorded, with the earliest ones being described in the Book of Songs (770\–476 BCE). How locust outbreaks endangered regimes and changed the destiny of China is also described in two other important ancient Chinese books \– Zizhi Tongjian (which covers Chinese history from 403 BCE to 959 CE, including 16 dynasties) and Ch\’ien Han Shu (which covers Chinese history from 206 BCE to 25 CE). Although the recorded histories of Australia and the Americas are more recent, orthopteran outbreaks have a long history on these continents as well. The first recorded outbreak of the Australian plague locust (Chortoicetes terminifera (Walker)) was in 1844, followed by outbreaks from the 1870s onward (including multiple outbreaks in the early 2000s, most of which were controlled by the Australian Plague Locust Commission (Hunter 2004)). In the United States, massive outbreaks of the Rocky Mountain locust (Melanoplus spretus (Walsh)) were recorded in the 1870s. The largest of the swarms covered a \“swath equal to the combined areas of Connecticut, Delaware, Maine, Maryland, Massachusetts, New Hampshire, New Jersey, New York, Pennsylvania, Rhode Island and Vermont\” (Riley et al. 1880), and nearly derailed westward expansion. Charles Valentine Riley, now considered one of the founding fathers of entomology in the United States, was appointed by the US government to investigate these outbreaks. His work led him to request further federal assistance, which the government provided in the form of the US Entomological Commission; this agency quickly morphed into the US Department of Agriculture that still operates today. The last known Rocky Mountain locust swarm occurred in the very early 1900s; why it disappeared remains a mystery, although some interesting hypotheses have been proposed (Lockwood 2005). The Mormon cricket (Anabrus simplex (Haldeman)) is another orthopteran species renowned for its outbreaks. Populations of Mormon crickets usually occur at low densities throughout most of their range in western North America, but population explosions that exceed more than 1 million individuals, marching in roving bands at densities of more than 100 individuals/m2 , are not uncommon. In 1848 a Mormon cricket outbreak nearly thwarted the settlement of Salt Lake City, Utah, by Mormon pioneers. Although the story is controversial, Mormon folklore recounts the miracle of the gulls. Legend claims that legions of seagulls, sent by God, appeared on June 9, 1848. These seagulls saved the settler\’s crops by eating all the crickets. South America and Central America also have orthopterans that show outbreak dynamics, the most notable being Schistocerca cancellata (Serville) and Schistocerca piceifrons (Walker), respectively. Given the devastation and immense suffering inflicted on humans by orthopteran outbreaks, it is pressing to understand the causal factors that contribute to their outbreaks. With the exception of Mormon crickets (see Sword 2005), the orthopterans described above exhibit phase polyphenism \– defined by Hardie and Lees (1985, 473) as \“occurrence of two or more distinct phenotypes which can be induced in individuals of the same genotype by extrinsic factors.\” The African desert locust and African migratory locust are easily two of the best-known species to practice phase polyphenism. However, many orthopterans that do not exhibit phase polyphenism can also undergo outbreaks, as has been the case for many grasshopper species in the western United States (Branson et al. 2006). In this chapter we concentrate primarily on orthopterans, but our aim is to understand factors that contribute to insect herbivore outbreaks more generally. We also discuss other types of insects, particularly lepidopterans, to make our points. Because insect outbreaks cannot happen without an initial increase in population size, we begin by focusing on individuals while considering factors, especially nutritional ones, that contribute to increased performance. We next explore how behavior and performance (e.g., survival, growth, and reproduction) of individual insect herbivores change as population densities increase. Shifting gears, we then discuss how ecological paradigms, particularly the \“plant stress hypothesis,\” have influenced how we view insect herbivore outbreaks. We conclude the chapter by calling for an integrative approach that translates individual responses into group-level phenomena, couched within the contexts of their communities and ecosystems.

}, keywords = {LTER-KNZ}, url = {http://behmerlab.tamu.edu/Resources/Behmer\%20\%26\%20Joern\%20(IOR-2012).pdf}, author = {Behmer, S.T. and Anthony Joern}, editor = {Barbosa, P. and Letourneau, D. and Agrawaal, A.} } @mastersthesis {KNZ001494, title = {An iPhone application of Konza Prairie LTER}, volume = {MS Thesis}, year = {2012}, pages = {1 -47}, school = {Kansas State University}, type = {M.S. Thesis}, address = {Manhattan, KS}, keywords = {LTER-KNZ}, url = {http://krex.k-state.edu/dspace/handle/2097/13960}, author = {Nukala, L.A.} } @article {KNZ001481, title = {Measuring genetic diversity in ecological studies}, journal = {Plant Ecology}, volume = {213}, year = {2012}, pages = {1105 -1115}, abstract = {


}, keywords = {LTER-KNZ, Community diversity, Ecosystem function, Genome diversity, Phenotype, SGDC}, doi = {10.1007/s11258-012-0069-6}, url = {https://link.springer.com/article/10.1007\%2Fs11258-012-0069-6}, author = {M.L. Avolio and Beaulieu, J. and Lo, E. and M.D. Smith} } @article {KNZ001484, title = {Sensitivity of mean annual primary production to precipitation}, journal = {Global Change Biology}, volume = {18}, year = {2012}, pages = {2246 -2255}, abstract = {

In many terrestrial ecosystems, variation in aboveground net primary production (ANPP) is positively correlated with variation in interannual precipitation. Global climate change will alter both the mean and the variance of annual precipitation, but the relative impact of these changes in precipitation on mean ANPP remains uncertain. At any given site, the slope of the precipitation-ANPP relationship determines the sensitivity of mean ANPP to changes in mean precipitation, whereas the curvature of the precipitation-ANPP relationship determines the sensitivity of ANPP to changes in precipitation variability. We used 58 existing long-term data sets to characterize precipitation-ANPP relationships in terrestrial ecosystems and to quantify the sensitivity of mean ANPP to the mean and variance of annual precipitation. We found that most study sites have a nonlinear, saturating relationship between precipitation and ANPP, but these nonlinearities were not strong. As a result of these weak nonlinearities, ANPP was nearly 40 times more sensitive to precipitation mean than variance. A 1\% increase in mean precipitation caused a \−0.2\% to 1.8\% change in mean ANPP, with a 0.64\% increase on average. Sensitivities to precipitation mean peaked at sites with a mean annual precipitation near 500 mm. Changes in species composition and increased intra-annual precipitation variability could lead to larger ANPP responses to altered precipitation regimes than predicted by our analysis.

}, keywords = {LTER-KNZ}, doi = {10.1111/j.1365-2486.2012.02687.x}, url = {https://onlinelibrary.wiley.com/doi/abs/10.1111/j.1365-2486.2012.02687.x}, author = {Hsu, J.S. and Powell, J. and P. Adler} } @article {KNZ001455, title = {Abundance of introduced species at home predicts abundance away in herbaceous communities}, journal = {Ecology Letters}, volume = {14}, year = {2011}, pages = {274 -281}, keywords = {LTER-KNZ}, doi = {10.1111/j.1461-0248.2010.01584.x}, url = {https://onlinelibrary.wiley.com/doi/abs/10.1111/j.1461-0248.2010.01584.x}, author = {Firn, J. and Joslin L. Moore and MacDougall, A.S. and E.T. Borer and Seabloom, E.W. and HilleRisLambers, J. and Harpole, W.S. and Cleland, E.E. and C.S. Brown and Knops, J.M.H. and Prober, S.M. and Pyke, D.A. and Farrell, K.A. and J.D. Bakker and O{\textquoteright}Halloran, L.R. and P. Adler and Scott. L. Collins and D{\textquoteright}Antonio, C.M. and Crawley, M.J. and Wolkovich, E.M. and Kimberly J. La Pierre and Melbourne, B.A. and Hautier, Y. and J.W. Morgan and Leakey, A.D.B. and Kay, A.D. and McCulley, R. and Davies, K.F. and Stevens, C.J. and Chu, C. and Holl, K.D. and Klein, J.A. and Fay, P.A. and Hagenah, N. and Kirkman, K.P. and Buckley, Y.M.} } @article {KNZ001420, title = {Assessing fine-scale genotypic structure of a dominant species in native grasslands}, journal = {The American Midland Naturalist}, volume = {165}, year = {2011}, pages = {211 -224}, abstract = {


}, keywords = {LTER-KNZ}, doi = {10.1674/0003-0031-165.2.211}, url = {https://doi.org/10.1674/0003-0031-165.2.211}, author = {M.L. Avolio and Chang, C.C. and M.D. Smith} } @article {KNZ001368, title = {Demography of female Greater Prairie-Chickens in unfragmented grasslands in Kansas}, journal = {Avian Conservation and Ecology-Ecologie et Conservation des Oiseaux}, volume = {6}, year = {2011}, abstract = {Populations of Greater Prairie-Chickens (Tympanuchus cupido) have been declining because of loss and fragmentation of tallgrass prairie habitats, and management plans require contemporary demographic data. Our objectives were to determine whether maternal nutrition or predation were determinants of nesting success and female survival. We captured and radio-marked 43 females at four leks in natural, unfragmented prairie during a 4-year study. Reproductive potential was high because females laid large clutches (10.9 {\textpm} 0.3 eggs, n = 24), renested following clutch loss (22.2\%, n = 27 females), and had high egg viability (88.6 {\textpm} 5.0\% of eggs hatched; n = 7 nests), but reproductive traits were not correlated with female morphometrics (mass, or tarsus and keel lengths). Daily survival rate of nests was low (0.928, n = 34 nests) resulting in a predicted nest success rate of 7.4\% for a 35-day exposure period. We used known fate models to estimate weekly survival from telemetry data for 40 females. Weekly survival was 0.970 and the extrapolated survival rate for the 6-month breeding season was 45.7\%. Using time-since-marking Cormack-Jolly-Seber models for live encounter data to control for transience, annual apparent survival was 0.277 {\textpm} 0.081 SE for 55 marked females after initial capture, and 0.424 {\textpm} 0.139 during subsequent intervals. Survival of females was 1.6 to 2.0 times higher during the nonbreeding season than the breeding season, presumably because females are susceptible to predation during incubation and brood-rearing. Predation of nests and females may be the main demographic factors limiting population viability because predation, and not maternal nutrition, accounted for unexpectedly low nesting success and breeding season survival of Greater Prairie-Chickens in natural habitats. Future research should investigate rangeland practices that increase residual nesting cover or reduce predator impacts.}, keywords = {LTER-KNZ}, doi = {10.5751/ACE-00429-060102}, url = {http://www.ace-eco.org/vol6/iss1/art2}, author = {Augustine, J.K. and Sandercock, B.K.} } @article {KNZ001411, title = {Explaining temporal variation in above-ground productivity in a mesic grassland: the role of climate and flowering}, journal = {Journal of Ecology}, volume = {99}, year = {2011}, pages = {1250 -1262}, abstract = {


}, keywords = {LTER-KNZ}, doi = {10.1111/j.1365-2745.2011.01844.x}, url = {https://besjournals.onlinelibrary.wiley.com/doi/full/10.1111/j.1365-2745.2011.01844.x}, author = {Kimberly J. La Pierre and Yuan, S.H. and Chang, C.C. and M.L. Avolio and Hallett, L.M. and Schreck, T. and M.D. Smith} } @mastersthesis {KNZ001493, title = {Infiltration controls in a tallgrass prairie at a hillslope scale}, volume = {MS Thesis}, year = {2011}, pages = {1 -126}, school = {Kansas State University}, type = {M.S. Thesis}, address = {Manhattan, KS}, abstract = {

Infiltration capacity influences the ability of a soil to absorb and transmit water through macropores and micropores of the soil structure. Infiltration is primarily influenced by the soil type, which is dependent on a number of factors including parent material, climate, biological activity, and topography. Spatial controls of land use, land cover, soil texture, slope position, slope gradient and slope aspect are a few of the variables influencing infiltration capacity within a uniform soil type. The goals of the thesis are to (1) quantify the spatial distribution of soil hydraulic properties at the surface of a hillslope using one measurement method - the automated mini-disk tension infiltrometer - and several analysis methods, (2) determine the dependence of depth on soil hydraulic properties using two measurement methods, and (3) compare the results of the investigation with information from the soil survey and soil investigations. First, automated mini-disk infiltrometers were used to determine soil hydraulic properties at ten sites along a hillslope in Konza Prairie Natural Research Area. Several analysis methods were used to extract hydraulic conductivity and sorptivity values from the infiltration data. Next, large intact soil cores were extracted from three selected sites at the same hillslope and analyzed at six depths using a large disk infiltrometer. Finally, the six segments of the large soil cores were analyzed using the same methods as the field measurements with the mini-disk infiltrometers. The results of the field investigation at the ten sites show a variability of soil hydraulic properties over an assumed homogeneous landscape. The values of hydraulic conductivity and sorptivity are dependent on the method of analysis. An empirically based approach produced more realistic values than a physically based approach. The results of the laboratory investigation of the three extracted soil cores also show a dependence of method of analysis and measurement. In addition, the results show a complex relationship among landscape position, depth, and soil structure. Finally, while soil surveys and soil descriptions can provide detailed information on soil properties, an infiltration investigation at a detailed spatial scale provides quantitative values for soil hydraulic properties.

}, keywords = {LTER-KNZ, Hydraulic conductivity, Hydrology, Infiltration, Konza Prairie}, url = { http://hdl.handle.net/2097/13183}, author = {Auvenshine, S.D.} } @article {KNZ001437, title = {Land fragmentation under rapid urbanization: A cross-site analysis of Southwestern cities}, journal = {Urban Ecosystems}, volume = {14}, year = {2011}, pages = {429 -455}, abstract = {


}, keywords = {LTER-KNZ, Exurbanization, Land fragmentation, The US Southwest, Urban ecology}, doi = {10.1007/s11252-011-0157-8}, url = {https://link.springer.com/article/10.1007\%2Fs11252-011-0157-8}, author = {York, A.M. and Shrestha, M. and Boone, C.G. and Zhang, S. and J. A. Harrington and Prebyl, T.J. and Swann, A. and Agar, M. and Antolin, M.F. and Nolen, B. and Wright, J.B. and Skaggs, R.} } @article {KNZ001360, title = {Nitrous oxide emission from denitrification in stream and river networks}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {108}, year = {2011}, pages = {214 -219}, abstract = {

Nitrous oxide (N2O) is a potent greenhouse gas that contributes to climate change and stratospheric ozone destruction. Anthropogenic nitrogen (N) loading to river networks is a potentially important source of N2O via microbial denitrification that converts N to N2O and dinitrogen (N2). The fraction of denitrified N that escapes as N2O rather than N2 (i.e., the N2O yield) is an important determinant of how much N2O is produced by river networks, but little is known about the N2O yield in flowing waters. Here, we present the results of whole-stream 15N-tracer additions conducted in 72 headwater streams draining multiple land-use types across the United States. We found that stream denitrification produces N2O at rates that increase with stream water nitrate (NO3\−) concentrations, but that \<1\% of denitrified N is converted to N2O. Unlike some previous studies, we found no relationship between the N2O yield and stream water NO3\−. We suggest that increased stream NO3\− loading stimulates denitrification and concomitant N2O production, but does not increase the N2O yield. In our study, most streams were sources of N2O to the atmosphere and the highest emission rates were observed in streams draining urban basins. Using a global river network model, we estimate that microbial N transformations (e.g., denitrification and nitrification) convert at least 0.68 Tg\·y\−1 of anthropogenic N inputs to N2O in river networks, equivalent to 10\% of the global anthropogenic N2O emission rate. This estimate of stream and river N2O emissions is three times greater than estimated by the Intergovernmental Panel on Climate Change. Humans have more than doubled the availability of fixed nitrogen (N) in the biosphere, particularly through the production of N fertilizers and the cultivation of N-fixing crops (1). Increasing N availability is producing unintended environmental consequences including enhanced emissions of nitrous oxide (N2O), a potent greenhouse gas (2) and an important cause of stratospheric ozone destruction (3). The Intergovernmental Panel on Climate Change (IPCC) estimates that the microbial conversion of agriculturally derived N to N2O in soils and aquatic ecosystems is the largest source of anthropogenic N2O to the atmosphere (2). The production of N2O in agricultural soils has been the focus of intense investigation (i.e., \>1,000 published studies) and is a relatively well constrained component of the N2O budget (4). However, emissions of anthropogenic N2O from streams, rivers, and estuaries have received much less attention and remain a major source of uncertainty in the global anthropogenic N2O budget. Microbial denitrification is a large source of N2O emissions in terrestrial and aquatic ecosystems. Most microbial denitrification is a form of anaerobic respiration in which nitrate (NO3\−, the dominant form of inorganic N) is converted to dinitrogen (N2) and N2O gases (5). The proportion of denitrified NO3\− that is converted to N2O rather than N2 (hereafter referred to as the N2O yield and expressed as the mole ratio) partially controls how much N2O is produced via denitrification (6), but few studies provide information on the N2O yield in streams and rivers because of the difficulty of measuring N2 and N2O production in these systems. Here we report rates of N2 and N2O production via denitrification measured using whole-stream 15NO3\−-tracer experiments in 72 headwater streams draining different land-use types across the United States. This project, known as the second Lotic Intersite Nitrogen eXperiment (LINX II), provides unique whole-system measurements of the N2O yield in streams. Although N2O emission rates have been reported for streams and rivers (7, 8), the N2O yield has been studied mostly in lentic freshwater and marine ecosystems, where it generally ranges between 0.1 and 1.0\%, although yields as high as 6\% have been observed (9). These N2O yields are low compared with observations in soils (0\–100\%) (10), which may be a result of the relatively lower oxygen (O2) availability in the sediments of lakes and estuaries. However, dissolved O2 in headwater streams is commonly near atmospheric equilibrium and benthic algal biofilms can produce O2 at the sediment\–water interface, resulting in strong redox gradients more akin to those in partially wetted soils. Thus, streams may have variable and often high N2O yields, similar to those in soils (11). The N2O yield in headwater streams is of particular interest because much of the NO3\− input to rivers is derived from groundwater upwelling into headwater streams. Furthermore, headwater streams compose the majority of stream length within a drainage network and have high ratios of bioreactive benthic surface area to water volume (12).

}, keywords = {LTER-KNZ}, doi = {10.1073/pnas.1011464108}, url = {https://www.pnas.org/content/108/1/214}, author = {Beaulieu, J.K. and Tank, J.L. and Hamilton, S.K. and Wollheim, W.M. and Hall, R.O. and Mulholland, P.J. and Peterson, B.J. and L.R. Ashkenas and Cooper, L.W. and Dahm, C.N. and W. K. Dodds and Grimm, N.B. and Johnson, S.L. and W.H. McDowell and Poole, G.C. and Valett, H.M. and Arango, C.P. and Bernot, M.J. and Burgin, A.J. and Crenshaw, C. and Helton, A.M. and Johnson, L. and O{\textquoteright}Brien, J.M. and Potter, J.D. and Sheibley, R.W. and Sobota, D.J. and Thomas, S.M.} } @article {KNZ001448, title = {Productivity is a poor predictor of plant species richness}, journal = {Science}, volume = {333}, year = {2011}, pages = {1750 -1753}, abstract = {

For more than 30 years, the relationship between net primary productivity and species richness has generated intense debate in ecology about the processes regulating local diversity. The original view, which is still widely accepted, holds that the relationship is hump-shaped, with richness first rising and then declining with increasing productivity. Although recent meta-analyses questioned the generality of hump-shaped patterns, these syntheses have been criticized for failing to account for methodological differences among studies. We addressed such concerns by conducting standardized sampling in 48 herbaceous-dominated plant communities on five continents. We found no clear relationship between productivity and fine-scale (meters\−2) richness within sites, within regions, or across the globe. Ecologists should focus on fresh, mechanistic approaches to understanding the multivariate links between productivity and richness.

}, keywords = {LTER-KNZ}, doi = {10.1126/science.1204498}, url = {http://science.sciencemag.org/content/333/6050/1750}, author = {P. Adler and Seabloom, E.W. and E.T. Borer and Hillebrand, H. and Hautier, Y. and Hector, A. and Harpole, W.S. and O{\textquoteright}Halloran, L.R. and Grace, J.B. and Anderson, T.M. and J.D. Bakker and L.A. Biederman and C.S. Brown and Buckley, Y.M. and Calabrese, L.B. and Chu, C.J. and Cleland, E.E. and Scott. L. Collins and Cottingham, K.L. and Crawley, M.J. and Damschen, E.I. and Davies, K.F. and DeCrappeo, N.M. and Fay, P.A. and Firn, J. and Frater, P. and Gasarch, E.I. and Gruner, D.S. and Hagenah, N. and HilleRisLambers, J. and Humphries, H.C. and Jin, V.L. and Kay, A. and Kirkman, K.P. and Klein, J.A. and Knops, J.M.H. and Kimberly J. La Pierre and Lambrinos, J.G. and Li, W. and MacDougall, A.S. and McCulley, R.L. and Melbourne, B.A. and Mitchell, C.E. and Joslin L. Moore} } @article {KNZ001296, title = {Testosterone mediates mating success in Greater Prairie-Chickens}, journal = {Studies in Avian Biology}, volume = {39}, year = {2011}, pages = {195 -208}, keywords = {LTER-KNZ}, author = {Augustine, J.K. and Millspaugh, J.J. and Sandercock, B.K.} } @article {KNZ001423, title = {Thinking outside the channel: modeling nitrogen cycling in networked river ecosystems}, journal = {Frontiers in Ecology and the Environment}, volume = {9}, year = {2011}, pages = {229 -238}, abstract = {


}, keywords = {LTER-KNZ}, doi = {10.1890/080211}, url = {https://esajournals.onlinelibrary.wiley.com/doi/abs/10.1890/080211}, author = {Helton, A.M. and Poole, G.C. and Meyer, J.L. and Wollheim, W.M. and Peterson, B.J. and Mulholland, P.J. and Bernhardt, E.S. and Stanford, J.A. and Arango, C.P. and L.R. Ashkenas and Cooper, L.W. and W. K. Dodds and Gregory, S.V. and O{\textquoteright}Hall, R. and Hamilton, S.K. and Johnson, S.L. and W.H. McDowell and Potter, J.D. and Tank, J.L. and Thomas, S.M. and Valett, H.M. and Webster, J.R. and Lydia H. Zeglin} } @article {KNZ001348, title = {Validating remotely sensed land surface fluxes in heterogeneous terrain with large aperture scintillometry}, journal = {International Journal of Remote Sensing}, volume = {32}, year = {2011}, pages = {6295 -6314}, abstract = {

The Large Aperture Scintillometer (LAS) has emerged as one of the best tools for quantifying areal averaged fluxes over heterogeneous land surfaces. This is particularly useful as a validation of surface energy fluxes derived from satellite sources. We examine how changes in surface source area contributing to the scintillometer and eddy covariance measurements relate to satellite derived estimates of sensible heat flux. Field data were collected on the Konza Prairie in Northeastern Kansas, included data from two eddy covariance towers: one located on an upland, relatively flat homogeneous area, and the second located in a lowland area with generally higher biomass and moisture conditions. The large aperture scintillometer spanned both the upland and lowland areas and operated with a path length of approximately 1 km specifically to compare to Moderate Resolution Imaging Spectroradiometer (MODIS) derived estimates of surface fluxes. The upland station compares well with the LAS (correlation of 0.96), with the lowland station being slightly worse (correlation of 0.84). Data from the MODIS sensor was used to compute surface fluxes using the \‘triangle\’ method which combines the remotely sensed data with a soil-vegetation-atmosphere-transfer scheme and a fully developed atmospheric boundary layer model. The relative contribution to the surface observations is estimated using a simple footprint model. As wind direction varies, the relative contribution of upland and lowland sources contributing to the LAS measurements varies while the MODIS pixel contribution remains relatively constant. With the footprint model, we were able to evaluate the relationship between the LAS observations and the remotely sensed estimates of the surface energy balance. The MODIS derived sensible heat flux values correspond better to the LAS measurements (percentage error: 0.04) when there was a larger footprint compared to a time with a smaller footprint (percentage error:\ \−0.13). Results indicate that the larger the footprint, the better the agreement between satellite and surface observations.

}, keywords = {LTER-KNZ}, doi = {10.1080/01431161.2010.508058}, url = {https://doi.org/10.1080/01431161.2010.508058}, author = {N. Brunsell and J.M. Ham and Arnold, K.A.} } @article {KNZ001438, title = {Woody plant proliferation in North American drylands: A synthesis of impacts on ecosystem carbon balance}, journal = {Journal of Geophysical Research}, volume = {116}, year = {2011}, abstract = {

[1] Changes in the magnitude and direction of ecosystem carbon (C) balance accompanying woody plant encroachment are among the largest contributors to the uncertainty in the North American C budget. In this synthesis we identify the important species contributing to woody encroachment, summarize our current knowledge of aboveground and belowground C storage change with woody encroachment, and evaluate the range of human and natural disturbance factors that alter the course of C gains and losses within ecosystems experiencing woody encroachment. Available data indicate that relative to the historic vegetation, aboveground net primary production (ANPP) decreases with woody plant encroachment in arid regions (mean annual precipitation (MAP) \< 336 mm), but increases in semiarid and subhumid regions (on the order of 0.7 g C m\−2 yr\−1 per mm of MAP over 336 mm). Soil organic carbon response to woody plant encroachment ranged from losses of 6200 g C m\−2 to gains of 2700 g C m\−2 with an average accumulation of 385 g C m\−2 across all studies and did not appear to be closely coupled to ANPP. Taken together, in the absence of disturbance, woody encroachment appears to result in a net ecosystem C gain across most species and ecoregions. However, disturbance associated with wildfire, land management practices, and drought may quickly and significantly offset these gains and should be explicitly factored into regional-scale C balance estimates. Our findings may be used to better constrain future estimates of woody plant encroachment influences on the North American C budget.

}, keywords = {LTER-KNZ}, doi = {10.1029/2010JG001506}, url = {https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2010JG001506}, author = {Barger, N.N. and S.R. Archer and Campbell, J.L. and C. Huang and Morton, J.A. and Alan K. Knapp} } @article {KNZ001334, title = {Comparative genome scan detects host-related divergent selection in the grasshopper Hesperotettix viridis}, journal = {Molecular Ecology}, volume = {19}, year = {2010}, pages = {4012 -4028}, abstract = {

In this study, we used a comparative genome scan to examine patterns of population differentiation with respect to host plant use in Hesperotettix viridis, a Nearctic oligophagous grasshopper locally specialized on various Asteraceae including Solidago, Gutierrezia, and Ericameria. We identified amplified fragment length polymorphism (AFLP) loci with significantly elevated FST (outlier loci) in multiple different-host and same-host comparisons of populations while controlling for geographic distance. By comparing the number and identities of outlier loci in different-host vs. same-host comparisons, we found evidence of host plant-related divergent selection for some population comparisons (Solidago- vs. Gutierrezia-feeders), while other comparisons (Ericameria- vs. Gutierrezia-feeders) failed to demonstrate a strong role for host association in population differentiation. In comparisons of Solidago- vs. Gutierrezia-feeding populations, a relatively high number of outlier loci observed repeatedly in different-host comparisons (35\% of all outliers and 2.7\% of all 625 AFLP loci) indicated a significant role for host-related selection in contributing to overall genomic differentiation in this grasshopper. Mitochondrial DNA sequence data revealed a star-shaped phylogeny with no host- or geography-related structure, low nucleotide diversity, and high haplotype diversity, suggesting a recent population expansion. mtDNA data do not suggest a long period of isolation in separate glacial refugia but are instead more compatible with a single glacial refugium and more recent divergence in host use. Our study adds to research documenting heterogeneity in differentiation across the genome as a consequence of divergent natural selection, a phenomenon that may occur as part of the process of ecological speciation.

}, keywords = {LTER-KNZ}, doi = {10.1111/j.1365-294X.2010.04792.x}, url = {https://onlinelibrary.wiley.com/doi/abs/10.1111/j.1365-294X.2010.04792.x}, author = {Apple, J.L. and Grace, T. and Anthony Joern and Amand, P. and Wisely, S.M.} } @article {KNZ001424, title = {Contrasting trait responses in plant communities to experimental and geographic variation in precipitation}, journal = {New Phytologist}, volume = {188}, year = {2010}, pages = {565 -575}, abstract = {

\•Patterns of precipitation are likely to change significantly in the coming century, with important but poorly understood consequences for plant communities. Experimental and correlative studies may provide insight into expected changes, but little research has addressed the degree of concordance between these approaches. \•We synthesized results from four experimental water addition studies with a correlative analysis of community changes across a large natural precipitation gradient in the United States. We investigated whether community composition, summarized with plant functional traits, responded similarly to increasing precipitation among studies and sites. \•In field experiments, increased precipitation favored species with small seed size, short leaf life span and high leaf nitrogen (N) concentration. However, with increasing precipitation along the natural gradient, community composition shifted towards species with higher mean seed mass, longer leaf life span and lower leaf N concentrations. \•The differences in temporal and spatial scale of experimental manipulations and natural gradients may explain these contrasting results. Our results highlight the complexity of responses to climate change, and suggest that transient dynamics may not reflect long-term shifts in functional diversity and community composition. We propose a model of community change that incorporates these differences between short- and long-term responses to climate change.

}, keywords = {LTER-KNZ}, doi = {10.1111/j.1469-8137.2010.03382.x}, url = {https://nph.onlinelibrary.wiley.com/doi/full/10.1111/j.1469-8137.2010.03382.x}, author = {Sandel, B. and Goldstein, L.J. and Kraft, N.J. and Okie, J.G. and Shuldman, M.I. and Ackerly, D.D. and Cleland, E.E. and K.N. Suding} } @article {KNZ001300, title = {Fire and grazing in a mesic tallgrass prairie: impacts on plant species and functional traits}, journal = {Ecology}, volume = {91}, year = {2010}, pages = {1651 -1659}, abstract = {


}, keywords = {LTER-KNZ}, doi = {10.1890/09-0431.1}, url = {https://esajournals.onlinelibrary.wiley.com/doi/abs/10.1890/09-0431.1}, author = {Spasojevic, M.J. and Aicher, R.J. and Koch, G.R. and Marquardt, E.S. and Mirotchnick, N. and Troxler, T.G. and Scott. L. Collins} } @article {KNZ001347, title = {Inter-regional comparison of land-use effects on stream metabolism}, journal = {Freshwater Biology}, volume = {55}, year = {2010}, pages = {1874 -1890}, abstract = {1. Rates of whole-system metabolism (production and respiration) are fundamental indicators of ecosystem structure and function. Although first-order, proximal controls are well understood, assessments of the interactions between proximal controls and distal controls, such as land use and geographic region, are lacking. Thus, the influence of land use on stream metabolism across geographic regions is unknown. Further, there is limited understanding of how land use may alter variability in ecosystem metabolism across regions. 2. Stream metabolism was measured in nine streams in each of eight regions (n = 72) across the United States and Puerto Rico. In each region, three streams were selected from a range of three land uses: agriculturally influenced, urban-influenced, and reference streams. Stream metabolism was estimated from diel changes in dissolved oxygen concentrations in each stream reach with correction for reaeration and groundwater input. 3. Gross primary production (GPP) was highest in regions with little riparian vegetation (sagebrush steppe in Wyoming, desert shrub in Arizona/New Mexico) and lowest in forested regions (North Carolina, Oregon). In contrast, ecosystem respiration (ER) varied both within and among regions. Reference streams had significantly lower rates of GPP than urban or agriculturally influenced streams. 4. GPP was positively correlated with photosynthetically active radiation and autotrophic biomass. Multiple regression models compared using Akaike{\textquoteright}s information criterion (AIC) indicated GPP increased with water column ammonium and the fraction of the catchment in urban and reference land-use categories. Multiple regression models also identified velocity, temperature, nitrate, ammonium, dissolved organic carbon, GPP, coarse benthic organic matter, fine benthic organic matter and the fraction of all land-use categories in the catchment as regulators of ER. 5. Structural equation modelling indicated significant distal as well as proximal control pathways including a direct effect of land-use on GPP as well as SRP, DIN, and PAR effects on GPP; GPP effects on autotrophic biomass, organic matter, and ER; and organic matter effects on ER. 6. Overall, consideration of the data separated by land-use categories showed reduced inter-regional variability in rates of metabolism, indicating that the influence of agricultural and urban land use can obscure regional differences in stream metabolism.}, keywords = {LTER-KNZ}, doi = {10.1111/j.1365-2427.2010.02422.x}, author = {Bernot, M.J. and Sobota, D.J. and Hall, R.O. and Mulholland, P.J. and W. K. Dodds and Webster, J.R. and Tank, J.L. and L.R. Ashkenas and Cooper, L.W. and Dahm, C.N. and Gregory, S.V. and Grimm, N.B. and Hamilton, S.K. and Johnson, S.L. and W.H. McDowell and Meyer, J.L. and Peterson, B. and Poole, G.C. and Valett, H.M. and Arango, C.P. and Beaulieu, J.J. and Burgin, A.J. and Crenshaw, C. and Helton, A.M. and Johnson, L. and Merriam, J. and Niederlehner, B.R. and O{\textquoteright}Brien, J.M. and Potter, J.D. and Sheibley, R.W. and Thomas, S.M. and Wilson, K.} } @article {KNZ001294, title = {Long-term community dynamics of small landbirds with and without exposure to extensive disturbance from military training activities}, journal = {Environmental Management}, volume = {45}, year = {2010}, pages = {203 -216}, abstract = {Military training activities are known to impact individual species, yet our understanding of how such activities influence animal communities is limited. In this study, we used long-term data in a case study approach to examine the extent to which the local small landbird community differed between a site in northeast Kansas that experienced intensive disturbance from military training activities (Ft. Riley Military Installation) and a similar, nearby site that experienced minimal human disturbance (Konza Prairie Biological Station). In addition, we characterized how the regional pool of potential colonizers influenced local community dynamics using Breeding Bird Survey data. From 1991 to 2001, most species of small terrestrial landbirds (73\%) recorded during breeding surveys were found at both sites and the mean annual richness at Ft. Riley (39.0 {\textpm} 2.86 [SD]) was very similar to that of Konza Prairie (39.4 {\textpm} 2.01). Richness was maintained at relatively constant levels despite compositional changes because colonizations compensated local extinctions at both sites. These dynamics were driven primarily by woodland species that exhibited stochastic losses and gains and were present at a low local and regional abundance. Our results suggest that military training activities may mimic natural disturbances for some species in this area because the small landbird community did not differ markedly between sites with and sites without extensive human disturbance. Although our results suggest that military training is not associated with large changes in the avian community, additional studies are needed to determine if this pattern is found in other ecological communities.}, keywords = {LTER-KNZ, Anthropogenic disturbance, Community dynamics, Grassland birds, Military training, Songbird conservation}, doi = {10.1007/s00267-009-9421-6}, author = {Rivers, J.W. and Gipson, P.S. and Althoff, D.P. and Pontius, J.S.} } @article {KNZ001529, title = {Permanent genetic resources added to molecular ecology resources database}, journal = {Molecular Ecology Resources}, volume = {9}, year = {2010}, month = {2010-01-01 00:00}, pages = {1559}, chapter = {1460}, abstract = {

This article documents the addition of 512 microsatellite marker loci and nine pairs of Single Nucleotide Polymorphism (SNP) sequencing primers to the Molecular Ecology Resources Database. Loci were developed for the following species: Alcippe morrisonia morrisonia, Bashania fangiana, Bashania fargesii, Chaetodon vagabundus, Colletes floralis, Coluber constrictor flaviventris, Coptotermes gestroi, Crotophaga major, Cyprinella lutrensis, Danaus plexippus, Fagus grandifolia, Falco tinnunculus, Fletcherimyia fletcheri, Hydrilla verticillata, Laterallus jamaicensis coturniculus, Leavenworthia alabamica, Marmosops incanus, Miichthys miiuy, Nasua nasua, Noturus exilis, Odontesthes bonariensis, Quadrula fragosa, Pinctada maxima, Pseudaletia separata, Pseudoperonospora cubensis, Podocarpus elatus, Portunus trituberculatus, Rhagoletis cerasi, Rhinella schneideri, Sarracenia alata, Skeletonema marinoi, Sminthurus viridis, Syngnathus abaster, Uroteuthis (Photololigo) chinensis, Verticillium dahliae, Wasmannia auropunctata, and Zygochlamys patagonica. These loci were cross-tested on the following species: Chaetodon baronessa, Falco columbarius, Falco eleonorae, Falco naumanni, Falco peregrinus, Falco subbuteo, Didelphis aurita, Gracilinanus microtarsus, Marmosops paulensis, Monodelphis Americana, Odontesthes hatcheri, Podocarpus grayi, Podocarpus lawrencei, Podocarpus smithii, Portunus pelagicus, Syngnathus acus, Syngnathus typhle,Uroteuthis (Photololigo) edulis, Uroteuthis (Photololigo) duvauceli and Verticillium albo-atrum. This article also documents the addition of nine sequencing primer pairs and sixteen allele specific primers or probes for Oncorhynchus mykiss and Oncorhynchus tshawytscha; these primers and assays were cross-tested in both species.

}, keywords = {LTER-KNZ}, doi = {10.1111/j.1755-0998.2009.02759.x}, url = {https://onlinelibrary.wiley.com/doi/abs/10.1111/j.1755-0998.2009.02759.x}, author = {Glenn R. Almany} } @article {KNZ001266, title = {Relatedness of Macrophomina phaseolina isolates from tallgrass prairie, maize, soybean, and sorghum}, journal = {Molecular Ecology}, volume = {19}, year = {2010}, pages = {79 -91}, abstract = {

Agricultural and wild ecosystems may interact through shared pathogens such as Macrophomina phaseolina, a generalist clonal fungus with more than 284 plant hosts that is likely to become more important under climate change scenarios of increased heat and drought stress. To evaluate the degree of subdivision in populations of M. phaseolina in Kansas agriculture and wildlands, we compared 143 isolates from maize fields adjacent to tallgrass prairie, nearby sorghum fields, widely dispersed soybean fields and isolates from eight plant species in tallgrass prairie. Isolate growth phenotypes were evaluated on a medium containing chlorate. Genetic characteristics were analysed based on amplified fragment length polymorphisms and the sequence of the rDNA-internal transcribed spacer (ITS) region. The average genetic similarity was 58\% among isolates in the tallgrass prairie, 71\% in the maize fields, 75\% in the sorghum fields and 80\% in the dispersed soybean fields. The isolates were divided into four clusters: one containing most of the isolates from maize and soybean, two others containing isolates from wild plants and sorghum, and a fourth containing a single isolate recovered from Solidago canadensis in the tallgrass prairie. Most of the sorghum isolates had the dense phenotype on media containing chlorate, while those from other hosts had either feathery or restricted phenotypes. These results suggest that the tallgrass prairie supports a more diverse population of M. phaseolina per area than do any of the crop species. Subpopulations show incomplete specialization by host. These results also suggest that inoculum produced in agriculture may influence tallgrass prairie communities, and conversely that different pathogen subpopulations in tallgrass prairie can interact there to generate \‘hybrids\’ with novel genetic profiles and pathogenic capabilities.

}, keywords = {LTER-KNZ}, doi = {10.1111/j.1365-294X.2009.04433.x}, url = {https://onlinelibrary.wiley.com/doi/abs/10.1111/j.1365-294X.2009.04433.x}, author = {Saleh, A.A. and Ahmed, H.U. and Todd, T.C. and Travers, S.E. and Zeller, K.A. and Leslie, J.F. and Garrett, K.A.} } @inbook {KNZ001256, title = {Challenges and approaches to statistical design and inference in high dimensional investigations}, booktitle = {Plant Systems Biology, Methods in Molecular Biology Series}, year = {2009}, pages = {181 -206}, publisher = {The Humana Press Inc}, organization = {The Humana Press Inc}, address = {Totowa, NJ}, abstract = {

Advances in modern technologies have facilitated high-dimensional experiments (HDEs) that generate tremendous amounts of genomic, proteomic, and other \“omic\” data. HDEs involving whole-genome sequences and polymorphisms, expression levels of genes, protein abundance measurements, and combinations thereof have become a vanguard for new analytic approaches to the analysis of HDE data. Such situations demand creative approaches to the processes of statistical inference, estimation, prediction, classification, and study design. The novel and challenging biological questions asked from HDE data have resulted in many specialized analytic techniques being developed. This chapter discusses some of the unique statistical challenges facing investigators studying high-dimensional biology and describes some approaches being developed by statistical scientists. We have included some focus on the increasing interest in questions involving testing multiple propositions simultaneously, appropriate inferential indicators for the types of questions biologists are interested in, and the need for replication of results across independent studies, investigators, and settings. A key consideration inherent throughout is the challenge in providing methods that a statistician judges to be sound and a biologist finds informative.

}, keywords = {LTER-KNZ, FDR, genomics, high-dimensional, microarray, multiple testing, statistics}, doi = {10.1007/978-1-60327-563-7_9}, url = {https://link.springer.com/protocol/10.1007\%2F978-1-60327-563-7_9}, author = {Gadbury, G.L. and Garrett, K.A. and Allison, D.B.}, editor = {Belostotsky, D.A.} } @mastersthesis {KNZ001333, title = {Estimating annual net primary productivity of the tallgrass prairie ecosystem of the Central Great Plains using AVHRR NDVI}, volume = {MS Thesis}, year = {2009}, school = {University of Kansas}, type = {M.S. Thesis}, address = {Lawrence, Kansas}, abstract = {


}, keywords = {LTER-KNZ}, url = {http://hdl.handle.net/1808/5393}, author = {An, N.} } @article {KNZ001273, title = {Highly polymorphic microsatellites in the North American snakeweed grasshopper, Hesperotettix viridis}, journal = {Journal of Orthoptera Research}, volume = {18}, year = {2009}, pages = {19 -21}, abstract = {

Microsatellite markers are preferred for fine-scale population genetic studies requiring high resolution. The grasshopper Hesperotettix viridis (Thomas) is an oligophagous species that feeds on composites and often exhibits locally restricted diets. Divergence in host plant use in some localities is seen where co-occurring subpopulations select alternate plant species, as expected with the evolution of host shifts and associated lineage divergence. To characterize the host-associated divergence patterns among populations of H. viridis, we developed markers from two microsatellite-enriched genomic libraries. Here we report the characterization and optimization of seven polymorphic di- and tri-nucleotide microsatellite loci for this species. One hundred and six individuals from 5 populations were tested for polymorphism. The number of alleles varied from 4 to 38 in all the populations. Ho ranged from 0.339 to 0.790. Homozygote excess was observed across loci, perhaps due to inbreeding. This is the first report of microsatellite markers for the subfamily Melanoplinae.

}, keywords = {LTER-KNZ, Hesperotettix viridis, host-associated divergence, local adaptation, microsatellite markers, snakeweed grasshopper}, doi = {10.1665/034.018.0111}, url = {https://bioone.org/journals/Journal-of-Orthoptera-Research/volume-18/issue-1/034.018.0111/Highly-Polymorphic-Microsatellites-in-the-North-American-Snakeweed-Grasshopper-iHesperotettix/10.1665/034.018.0111.full}, author = {Grace, T. and Anthony Joern and Brown, S.J. and Apple, J.L. and Wisely, S.M.} } @article {KNZ001255, title = {Limiting temperatures for urediniospore germination are low in a systemic rust fungus of tallgrass prairie}, journal = {Mycologia}, volume = {101}, year = {2009}, pages = {390 -394}, abstract = {

Potential responses of plant disease phenology to climate change have been addressed primarily in agricultural systems. As a first step toward understanding the phenology of Uropyxis petalostemonis, a rust fungus commonly infecting the legume Dalea candida in USA tallgrass prairie, we evaluated the effects of temperature on urediniospore germination. While urediniospore germination for many rust fungi has been reported to decline only when temperatures are well above 25 C, in vitro germination of U petalostemonis dropped sharply at this temperature. Responses observed on water agar, potato dextrose agar and lima bean agar were similar, although lima bean agar supported a higher percentage germination overall. The low limiting temperatures suggest that most epidemically important new infections by U petalostemonis occur in spring. High summer temperatures in tallgrass prairie might push infection by this rust fungus species to earlier in the year and select for stronger systemic growth characteristics.

}, keywords = {LTER-KNZ, Basidiomycetes, Dalea candida, Fabaceae, phenology, Uredinales, Uropyxis petalostemonis}, doi = {10.3852/08-102}, url = {https://www.tandfonline.com/doi/abs/10.3852/08-102?journalCode=umyc20}, author = {Worapong, J. and Dendy, S.P. and Tang, Z. and Awl, D.J. and Garrett, K.A.} } @article {KNZ001250, title = {Nitrate removal in stream ecosystems measured by 15N addition experiments: Total uptake}, journal = {Limnology and Oceanography}, volume = {54}, year = {2009}, pages = {653 -665}, abstract = {

We measured uptake length of 15NO3\− in 72 streams in eight regions across the United States and Puerto Rico to develop quantitative predictive models on controls of NO3\− uptake length. As part of the Lotic Intersite Nitrogen eXperiment II project, we chose nine streams in each region corresponding to natural (reference), suburban-urban, and agricultural land uses. Study streams spanned a range of human land use to maximize variation in NO3\− concentration, geomorphology, and metabolism. We tested a causal model predicting controls on NO3\− uptake length using structural equation modeling. The model included concomitant measurements of ecosystem metabolism, hydraulic parameters, and nitrogen concentration. We compared this structural equation model to multiple regression models which included additional biotic, catchment, and riparian variables. The structural equation model explained 79\% of the variation in log uptake length (SWtot). Uptake length increased with specific discharge (Q/w) and increasing NO3\− concentrations, showing a loss in removal efficiency in streams with high NO3\− concentration. Uptake lengths shortened with increasing gross primary production, suggesting autotrophic assimilation dominated NO3\− removal. The fraction of catchment area as agriculture and suburban-urban land use weakly predicted NO3\− uptake in bivariate regression, and did improve prediction in a set of multiple regression models. Adding land use to the structural equation model showed that land use indirectly affected NO3\− uptake lengths via directly increasing both gross primary production and NO3\− concentration. Gross primary production shortened SWtot, while increasing NO3\− lengthened SWtot resulting in no net effect of land use on NO3\− removal.

}, keywords = {LTER-KNZ}, doi = {10.4319/lo.2009.54.3.0653}, url = {https://aslopubs.onlinelibrary.wiley.com/doi/abs/10.4319/lo.2009.54.3.0653}, author = {Hall, R.O. Jr. and Tank, J.L. and Sobota, D.J. and Mulholland, P.J. and O{\textquoteright}Brien, J.M. and W. K. Dodds and Webster, J.R. and Valett, H.M. and Poole, G.C. and Peterson, B.J. and Meyer, J.L. and W.H. McDowell and Johnson, S.L. and Hamilton, S.K. and Grimm, N.B. and Gregory, S.V. and Dahm, C.N. and Cooper, L.W. and L.R. Ashkenas and Thomas, S.M. and Sheibley, R.W. and Potter, J.D. and Niederlehner, B.R. and Johnson, L.T. and Helton, A.M. and Crenshaw, C.M. and Burgin, A.J. and Bernot, M.J. and Beaulieu, J.J. and Arango, C.P.} } @article {KNZ001251, title = {Nitrate removal in stream ecosystems measured by 15N addition experiments: Denitrification}, journal = {Limnology and Oceanography}, volume = {54}, year = {2009}, pages = {666 -680}, abstract = {

We measured denitrification rates using a field 15NO3\− tracer-addition approach in a large, cross-site study of nitrate uptake in reference, agricultural, and suburban-urban streams. We measured denitrification rates in 49 of 72 streams studied. Uptake length due to denitrification (SWdenn) ranged from 89 m to 184 km (median of 9050 m) and there were no significant differences among regions or land-use categories, likely because of the wide range of conditions within each region and land use. N2 production rates far exceeded N2O production rates in all streams. The fraction of total NO3\− removal from water due to denitrification ranged from 0.5\% to 100\% among streams (median of 16\%), and was related to NH4+ concentration and ecosystem respiration rate (ER). Multivariate approaches showed that the most important factors controlling SWden were specific discharge (discharge / width) and NO3\− concentration (positive effects), and ER and transient storage zones (negative effects). The relationship between areal denitrification rate (Uden) and NO3\− concentration indicated a partial saturation effect. A power function with an exponent of 0.5 described this relationship better than a Michaelis-Menten equation. Although Uden increased with increasing NO3\− concentration, the efficiency of NO3\− removal from water via denitrification declined, resulting in a smaller proportion of streamwater NO3\− load removed over a given length of stream. Regional differences in stream denitrification rates were small relative to the proximate factors of NO3\− concentration and ecosystem respiration rate, and land use was an important but indirect control on denitrification in streams, primarily via its effect on NO3\− concentration.

}, keywords = {LTER-KNZ}, doi = {10.4319/lo.2009.54.3.0666}, url = {https://aslopubs.onlinelibrary.wiley.com/doi/abs/10.4319/lo.2009.54.3.0666}, author = {Mulholland, P.J. and Hall, R.O. and Sobota, D.J. and W. K. Dodds and Findlay, S.E.G. and Grimm, N.B. and Hamilton, S.K. and W.H. McDowell and O{\textquoteright}Brien, J.M. and Tank, J.L. and L.R. Ashkenas and Cooper, L.W. and Dahm, C.N. and Gregory, S.V. and Johnson, S.L. and Meyer, J.L. and Peterson, B.J. and Poole, G.C. and Valett, H.M. and Webster, J.R. and Arango, C.P. and Beaulieu, J.J. and Bernot, M.J. and Burgin, A.J. and Crenshaw, C.L. and Helton, A.M. and Johnson, L.T. and Niederlehner, B.R. and Potter, J.D. and Sheibley, R.W. and Thomas, S.M.} } @article {KNZ001186, title = {Tracking the rhythm of the seasons in the face of global change: phenological research in the 21st century}, journal = {Frontiers in Ecology and the Environment}, volume = {7}, year = {2009}, pages = {253 -260}, abstract = {


}, keywords = {LTER-KNZ}, doi = {10.1890/070217}, url = {https://esajournals.onlinelibrary.wiley.com/doi/abs/10.1890/070217}, author = {Morisette, J.T. and Richardson, A.D. and Alan K. Knapp and Fisher, J.I. and Graham, E.A. and Abatzoglou, J. and Wilson, B.E. and Breshears, D.D. and Henebry, G.M. and Hanes, J.M. and Liang, L.} } @article {KNZ001227, title = {Antibiotic resistance of Enterococci in American bison (Bison bison) from a nature preserve compared to that of Enterococci in pastured cattle}, journal = {Applied and Environmental Microbiology}, volume = {74}, year = {2008}, pages = {1726 -1730}, abstract = {

Enterococci isolated from a bison population on a native tall-grass prairie preserve in Kansas were characterized and compared to enterococci isolated from pastured cattle. The species diversity was dominated by Enterococcus casseliflavus in bison (62.4\%), while Enterococcus hirae was the most common isolate from cattle (39.7\%). Enterococcus faecalis was the second most common species isolated from bison (16\%). In cattle, E. faecalis and Enterococcus faecium were isolated at lower percentages (3.2\% and 1.6\%, respectively). No resistance to ampicillin, chloramphenicol, gentamicin, or high levels of vancomycin was detected from either source. Tetracycline and erythromycin resistance phenotypes, encoded by tetO and ermB, respectively, were common in cattle isolates (42.9\% and 12.7\%, respectively). A significant percentage of bison isolates (8\% and 4\%, respectively) were also resistant to these two antibiotics. The tetracycline resistance genes from both bison and cattle isolates resided on mobile genetic elements and showed a transfer frequency of 10\−6 per donor, whereas erythromycin resistance was not transferable. Resistance to ciprofloxacin was found to be higher in enterococci from bison (14.4\%) than in enterococci isolated from cattle (9.5\%). The bison population can serve as a sentinel population for studying the spread and origin of antibiotic resistance.

}, keywords = {LTER-KNZ}, doi = {10.1128/AEM.02164-07}, url = {https://aem.asm.org/content/74/6/1726}, author = {Anderson, J. F. and Parrish, T.D. and Akhtar, M. and Zurek, L. and Hirt, H.} } @article {KNZ001139, title = {Demographic sensitivity of population change in the Northern Bobwhite}, journal = {Journal of Wildlife Management}, volume = {72}, year = {2008}, pages = {970 -982}, abstract = {


}, keywords = {LTER-KNZ, Colinus virginianus, fecundity, life-stage simulation analysis, population model, quail, survival}, doi = {10.2193/2007-124}, url = {https://bioone.org/journals/journal-of-wildlife-management/volume-72/issue-4/2007-124/Demographic-Sensitivity-of-Population-Change-in-Northern-Bobwhite/10.2193/2007-124.short}, author = {Sandercock, B.K. and Jensen, W.E. and Williams, C.K. and Applegate, R.D.} } @article {KNZ001241, title = {Plant winners and losers during grassland N eutrophication differ in biomass allocation and mycorrhizas}, journal = {Ecology}, volume = {89}, year = {2008}, pages = {2868 -2878}, abstract = {

Human activities release tremendous amounts of nitrogenous compounds into the atmosphere. Wet and dry deposition distributes this airborne nitrogen (N) on otherwise pristine ecosystems. This eutrophication process significantly alters the species composition of native grasslands; generally a few nitrophilic plant species become dominant while many other species disappear. The functional equilibrium model predicts that, compared to species that decline in response to N enrichment, nitrophilic grass species should respond to N enrichment with greater biomass allocation aboveground and reduced allocation to roots and mycorrhizas. The mycorrhizal feedback hypothesis states that the composition of mycorrhizal fungal communities may influence the composition of plant communities, and it predicts that N enrichment may generate reciprocal shifts in the species composition of mycorrhizal fungi and plants. We tested these hypotheses with experiments that compared biomass allocation and mycorrhizal function of four grass ecotypes (three species), two that gained and two that lost biomass and cover in response to long-term N enrichment experiments at Cedar Creek and Konza Long-Term Ecological Research grasslands. Local grass ecotypes were grown in soil from their respective sites and inoculated with whole-soil inoculum collected from either fertilized (FERT) or unfertilized (UNFERT) plots. Our results strongly support the functional equilibrium model. In both grassland systems the nitrophilic grass species grew taller, allocated more biomass to shoots than to roots, and formed fewer mycorrhizas compared to the grass species that it replaced. Our results did not fully support the hypothesis that N-induced changes in the mycorrhizal fungal community were drivers of the plant community shifts that accompany N eutrophication. The FERT and UNFERT soil inoculum influenced the growth of the grasses differently, but this varied with site and grass ecotype in both expected and unexpected ways suggesting that ambient soil fertility or other factors may be interacting with mycorrhizal feedbacks.

}, keywords = {LTER-KNZ}, doi = {10.1890/07-1394.1}, url = {https://esajournals.onlinelibrary.wiley.com/doi/abs/10.1890/07-1394.1}, author = {Johnson, N.C. and Rowland, D.L. and Corkidi, L. and Allen, E.B.} } @article {KNZ001159, title = {Plasma cholinesterases for monitoring pesticide exposure in Nearctic-Neotropical migratory shorebirds}, journal = {Ornitholog{\'\i}a Neotropical}, volume = {19 (Suppl)}, year = {2008}, pages = {641 -651}, abstract = {Organophosphorus (OP) and carbamate (CB) pesticides are commonly used agrochemicals throughout the Western Hemisphere. These pesticides have caused mortalities in migratory birds and adverse physiological effects in trials with captive birds. Migratory shorebirds use a variety, of habitats during the austral summer in temperate South America and during migration through the Great Plains of the United States. Habitats where risk of exposure is high include rice fields and turf grass farms where agrochemicals are used. Cholinesterase (ChE) is a specific biomarker for monitoring OP and CB exposure and can be measured using standard laboratory procedures. Plasma ChE activity is useful as a non-lethal means of monitoring avian exposure to OP and CB pesticides. Many variables can affect enzyme activity and reactivation assays are not always possible, thus reference ChE values are a necessary component of monitoring exposure. During northbound migration in 2006, we sampled four upland and five wetland shore-bird species at four pesticide-free sites in North America, characterizing and measuring plasma ChEs in all shorebird species. Small-bodied species had higher levels of ChE activity in plasma than large-bodied species. Acetylcholinesterase (AChE), the enzyme whose inhibition leads to poisoning symptoms, showed less inter-specific variation than butyrylcholinesterase (BChE). Plasma ChE activities varied with date of capture in three of five species. Sex differences were significant in one of two species tested. Our baseline ChE values for migratory shorebirds provide a framework for future ecotoxicological studies of Nearctic-Neotropical migrant shorebirds.}, keywords = {LTER-KNZ}, url = {https://www.researchgate.net/publication/254414753_Plasma_cholinesterases_for_monitoring_pesticide_exposure_in_Nearctic-Neotropical_migratory_shorebirds}, author = {Strum, K.M. and Alfaro, M. and Haase, B. and Hooper, M.J. and Johnson, K.A. and Lanctot, R.B. and Lesterhuis, A.J. and L{\'o}pez, L. and Matz, A.C. and Morales, C. and Paulson, B. and Sandercock, B.K. and Torres-Dowdall, J. and Zaccagnini, M.E.} } @article {KNZ001149, title = {Shrub encroachment in North American grasslands: Shifts in growth form dominance rapidly alters control of ecosystem carbon inputs}, journal = {Global Change Biology}, volume = {14}, year = {2008}, pages = {615 -623}, abstract = {

Shrub encroachment into grass-dominated biomes is occurring globally due to a variety of anthropogenic activities, but the consequences for carbon (C) inputs, storage and cycling remain unclear. We studied eight North American graminoid-dominated ecosystems invaded by shrubs, from arctic tundra to Atlantic coastal dunes, to quantify patterns and controls of C inputs via aboveground net primary production (ANPP). Across a fourfold range in mean annual precipitation (MAP), a key regulator of ecosystem C input at the continental scale, shrub invasion decreased ANPP in xeric sites, but dramatically increased ANPP (\>1000 g m\−2) at high MAP, where shrub patches maintained extraordinarily high leaf area. Concurrently, the relationship between MAP and ANPP shifted from being nonlinear in grasslands to linear in shrublands. Thus, relatively abrupt (\<50 years) shifts in growth form dominance, without changes in resource quantity, can fundamentally alter continental-scale pattern of C inputs and their control by MAP in ways that exceed the direct effects of climate change alone.

}, keywords = {LTER-KNZ}, doi = {10.1111/j.1365-2486.2007.01512.x}, url = {https://onlinelibrary.wiley.com/doi/abs/10.1111/j.1365-2486.2007.01512.x}, author = {Alan K. Knapp and J. M. Briggs and Scott. L. Collins and S.R. Archer and Bret-Harte, M.S. and Ewers, B.E. and Peters, D.P. and Young, D.R. and Shaver, G.R. and Pendall, E. and Cleary, M.B.} } @article {KNZ001164, title = {Stream denitrification across biomes and its response to anthropogenic nitrate loading}, journal = {Nature}, volume = {452}, year = {2008}, pages = {202 -207}, abstract = {


}, keywords = {LTER-KNZ}, doi = {10.1038/nature06686}, url = {https://www.nature.com/articles/nature06686}, author = {Mulholland, P.J. and Helton, A.M. and Poole, G.C. and Hall, R.O. Jr. and Hamilton, S.K. and Peterson, B.J. and Tank, J.L. and L.R. Ashkenas and Cooper, L.W. and Dahm, C.N. and W. K. Dodds and Findlay, S.E.G. and Gregory, S.V. and Grimm, N.B. and Johnson, S.L. and W.H. McDowell and Meyer, J.L. and Valett, H.M. and Webster, J.R. and Arango, C.P. and Beaulieu, J.J. and Bernot, M.J. and Burgin, A.J. and Crenshaw, C. and Johnson, L. and Niederlehner, B.R. and O{\textquoteright}Brien, J.M. and Potter, J.D. and Sheibley, R.W. and Sobota, D.J. and Thomas, S.M.} } @article {KNZ001172, title = {Does species diversity limitproductivity in natural grassland communities?}, journal = {Ecology Letters}, volume = {10}, year = {2007}, pages = {680 -689}, abstract = {Theoretical analyses and experimental studies of synthesized assemblages indicate that under particular circumstances species diversity can enhance community productivity through niche complementarity. It remains unclear whether this process has important effects in mature natural ecosystems where competitive feedbacks and complex environmental influences affect diversity{\textendash}productivity relationships. In this study, we evaluated diversity{\textendash}productivity relationships while statistically controlling for environmental influences in 12 natural grassland ecosystems. Because diversity{\textendash}productivity relationships are conspicuously nonlinear, we developed a nonlinear structural equation modeling (SEM) methodology to separate the effects of diversity on productivity from the effects of productivity on diversity. Meta-analysis was used to summarize the SEM findings across studies. While competitive effects were readily detected, enhancement of production by diversity was not. These results suggest that the influence of small-scale diversity on productivity in mature natural systems is a weak force, both in absolute terms and relative to the effects of other controls on productivity.}, keywords = {LTER-KNZ}, doi = {10.1111/j.1461-0248.2007.01058.x}, author = {Grace, J.B. and Anderson, T.M. and M.D. Smith and Seabloom, E. and Andelman, S.J. and Meche, G. and Weiher, E. and Allain, L.K. and Jutila, H. and Sankaran, M. and Knops, J. and Ritchie, M. and M.R. Whiles} } @article {KNZ001146, title = {Global-scale similarities in nitrogen release patterns during long-term decomposition}, journal = {Science}, volume = {315}, year = {2007}, pages = {361 -364}, abstract = {Litter decomposition provides the primary source of mineral nitrogen (N) for biological activity in most terrestrial ecosystems. A 10-year decomposition experiment in 21 sites from seven biomes found that net N release from leaf litter is dominantly driven by the initial tissue N concentration and mass remaining regardless of climate, edaphic conditions, or biota. Arid grasslands exposed to high ultraviolet radiation were an exception, where net N release was insensitive to initial N. Roots released N linearly with decomposition and exhibited little net N immobilization. We suggest that fundamental constraints on decomposer physiologies lead to predictable global-scale patterns in net N release during decomposition.}, keywords = {LTER-KNZ}, doi = {10.1126/science.1134853}, author = {Parton, W.J. and Silver, W.L. and Burke, I.C. and Grassens, L. and Harmon, M.E. and Currie, W.S. and King, J.Y. and Adair, E.C. and Brandt, L.A. and Hart, S.C. and Fasth, B.} } @article {KNZ001161, title = {Mycorrhizal community dynamics following nitrogen fertilization: A cross site test in five grasslands}, journal = {Ecological Monographs}, volume = {77}, year = {2007}, pages = {524 -544}, abstract = {Arbuscular mycorrhizal fungi (AMF) are considered both ecologically and physiologically important to many plant communities. As a result, any alteration in AMF community structure following soil nitrogen (N) enrichment may impact plant community function and contribute to widespread changes in grassland productivity. We evaluated the responses of AMF communities to N fertilization (>=100 kg N{\textperiodcentered}ha-1{\textperiodcentered}yr-1) in five perennial grasslands within the Long-Term Ecological Research network to generate a broader understanding of the drivers contributing to AMF species richness and diversity with increasing soil N fertility, and subsequent effects to host-plant communities. AMF spore and hyphal community data at three mesic sites (Cedar Creek, Kellogg Biological Station, Konza Prairie) and two semiarid sites (Sevilleta, Shortgrass Steppe) were collected over two consecutive years and used to test four hypotheses about AMF responses to N fertilization. Under ambient soil N, plant annual net primary productivity and soil phosphorus (P) were strongly related to climatic differences in AMF communities (semiarid vs. mesic). Following N fertilization, the drivers of AMF community structure were soil N availability, N:P supply ratio, and host-plant photosynthetic strategy (C3 vs. C4) but not climate. In P-rich soils (low N:P), N fertilization reduced AMF productivity, species richness, and diversity and intensified AMF community convergence due to the loss of rare AMF species and the increased abundance of Glomus species. In P-limited soils (high N:P), AMF productivity, species richness, and diversity increased with N fertilization; the most responsive AMF taxa were Acaulospora, Scutellospora, and Gigaspora. Soil N or N:P {\texttimes} host-plant (C3, C4) interactions further modified these responses: AMF hyphae (primarily Gigasporaceae) associated with C3 plants increased in abundance with N fertilization, whereas C4 plants hosted nitrophilous Glomus species. Such responses were independent of the duration or quantity of N fertilization, or the time since cessation of N fertilization. This synthesis provides a new understanding of AMF community patterns and processes, and it identifies three key drivers (soil N, N:P, host plant) of AMF community structure that may be tested in other communities.}, keywords = {LTER-KNZ}, doi = {10.1890/06-1772.1}, author = {Egerton-Warburton, L.M. and Johnson, N.C. and Allen, E.B.} } @article {KNZ001016, title = {A comparison of the species-timerelationship across ecosystems and taxonomic groups}, journal = {Oikos}, volume = {112}, year = {2006}, pages = {185 -195}, abstract = {The species{\textendash}time relationship (STR) describes how the species richness of a community increases with the time span over which the community is observed. This pattern has numerous implications for both theory and conservation in much the same way as the species{\textendash}area relationship (SAR). However, the STR has received much less attention and to date only a handful of papers have been published on the pattern. Here we gather together 984 community time-series, representing 15 study areas and nine taxonomic groups, and evaluate their STRs in order to assess the generality of the STR, its consistency across ecosystems and taxonomic groups, its functional form, and its relationship to local species richness. In general, STRs were surprisingly similar across major taxonomic groups and ecosystem types. STRs tended to be well fit by both power and logarithmic functions, and power function exponents typically ranged between 0.2 and 0.4. Communities with high richness tended to have lower STR exponents, suggesting that factors increasing richness may simultaneously decrease turnover in ecological systems. Our results suggest that the STR is as fundamental an ecological pattern as the SAR, and raise questions about the general processes underlying this pattern. They also highlight the dynamic nature of most species assemblages, and the need to incorporate time scale in both basic and applied research on species richness patterns.}, keywords = {LTER-KNZ}, doi = {10.1111/j.0030-1299.2006.14223.x}, author = {White, E.P. and P. Adler and Lauenroth, W.K. and Gill, R.A. and Greenberg, D. and Kaufman, D.M. and Rassweiler, A. and Rusak, J.A. and M. A. Smith and Steinbeck, J. and Waide, R.B. and Yao, J.} } @article {KNZ001032, title = {Determining ecoregional reference conditions for nutrients, secchi depth, and chlorophyll a in Kansas lakes and reservoirs}, journal = {Lake and Reservoir Management}, volume = {22}, year = {2006}, pages = {151 -159}, abstract = {Baseline environmental conditions are a critical consideration in the development of scientifically defensible aquatic nutrient criteria. We applied three methods to ecoregionally stratified data to determine reference conditions in Kansas lakes and reservoirs with respect to total phosphorus, total nitrogen, Secchi depth, and planktonic chlorophyll a (chl a). First, minimally developed lake/watershed units were identified based on existing geographical databases and visual basin surveys. Lakes and reservoirs in these watersheds were considered minimally-to-least impacted {\textquotedblleft}reference{\textquotedblright} waters. Second, median nutrient, Secchi depth, and chl a values were determined for the best one-third of lakes and reservoirs and applied as indicators of reference condition (trisection). Third, a regression-based extrapolation method was applied to estimate water quality conditions in the absence of anthropogenic influences. The first method suggested no ecoregional effect on the trophic status of minimally impacted reference water bodies, whereas the other two methods indicated some significant ecoregional differences. Lack of ecoregional effect in reference bodies could indicate that differences were driven by anthropogenic influences rather than natural regional characteristics. Reference conditions, as determined by these three methods, broadly agreed for all parameters and were generally at or less than literature values for the mesotrophic-eutrophic threshold for lakes and reservoirs worldwide. Reference values for total phosphorus were primarily less than levels commonly associated with cyanobacterial blooms. Overall, the data suggest that multiple methods can be used to determine reference condition, and that in Kansas lakes and reservoirs reference condition corresponds to mesotrophic state.}, keywords = {LTER-KNZ, ecoregion, eutrophication, nitrogen, nutrient criteria, Phosphorus}, doi = {10.1080/07438140609353892}, author = {W. K. Dodds and Carney, E. and Angelo, R.T.} } @article {KNZ001152, title = {Evaluation of MODIS NPP and GPP products across multiple biomes}, journal = {Remote Sensing of Environment}, volume = {102}, year = {2006}, pages = {282 -292}, abstract = {Estimates of daily gross primary production (GPP) and annual net primary production (NPP) at the 1 km spatial resolution are now produced operationally for the global terrestrial surface using imagery from the MODIS (Moderate Resolution Imaging Spectroradiometer) sensor. Ecosystem-level measurements of GPP at eddy covariance flux towers and plot-level measurements of NPP over the surrounding landscape offer opportunities for validating the MODIS NPP and GPP products, but these flux measurements must be scaled over areas on the order of 25 km2 to make effective comparisons to the MODIS products. Here, we report results for such comparisons at 9 sites varying widely in biome type and land use. The sites included arctic tundra, boreal forest, temperate hardwood forest, temperate conifer forest, tropical rain forest, tallgrass prairie, desert grassland, and cropland. The ground-based NPP and GPP surfaces were generated by application of the Biome-BGC carbon cycle process model in a spatially-distributed mode. Model inputs of land cover and leaf area index were derived from Landsat data. The MODIS NPP and GPP products showed no overall bias. They tended to be overestimates at low productivity sites {\textemdash} often because of artificially high values of MODIS FPAR (fraction of photosynthetically active radiation absorbed by the canopy), a critical input to the MODIS GPP algorithm. In contrast, the MODIS products tended to be underestimates in high productivity sites {\textemdash} often a function of relatively low values for vegetation light use efficiency in the MODIS GPP algorithm. A global network of sites where both NPP and GPP are measured and scaled over the local landscape is needed to more comprehensively validate the MODIS NPP and GPP products and to potentially calibrate the MODIS NPP/GPP algorithm parameters.}, keywords = {LTER-KNZ, biomes, Global, Gross primary production, Landsat, MODIS, Monitoring, Net primary production, Validation}, doi = {10.1016/j.rse.2006.02.017}, author = {Turner, D.P. and Ritts, W.D. and Cohen, W.B. and Gower, S.T. and Running, SW. and Zhao, M. and Costa, M.H. and Kirschbaum, A. and J.M. Ham and Saleska, S. and Ahl, D.E.} } @article {KNZ00963, title = {Competition, facilitation, and niche differentiation in two foliar pathogens}, journal = {Oecologia}, volume = {143}, year = {2005}, pages = {449 -457}, abstract = {We studied competition between the obligate biotroph Puccinia triticina (designated here as Puccinia) and the facultative saprophyte Pyrenophora tritici-repentis (designated here as Pyrenophora) in older and younger leaves in a set of three host genotypes selected to be resistant to Puccinia only, Pyrenophora only, or neither. Age-related resistance is important for both of these pathogens. The facultative saprophyte Pyrenophora was generally a stronger competitor than the biotrophic Puccinia, even experiencing facilitation from the presence of Puccinia when Pyrenophora had the advantage of earlier inoculation. Both pathogen species produced the most spores when they were introduced before the competing species and more spores when introduced simultaneously compared to after the competitor. The pre-interactive niche of Puccinia was larger than the post-interactive niche and sporulation by Puccinia was substantially reduced in environments in which Pyrenophora had high sporulation rates. The pre-interactive niche of Pyrenophora was similar to the post-interactive niche and Pyrenophora had proportionally lower reductions in sporulation due to interspecific competition in the pre-interactive niche.}, keywords = {LTER-KNZ, Facultative saprophytes, Impact niche, Obligate parasites, Requirement niche, Rust fungi}, doi = {10.1007/s00442-004-1814-x}, author = {Al-Naimi, F. and Garrett, K.A. and Bockus, W.W.} } @article {KNZ001008, title = {Evidence for a general species-time-area relationship}, journal = {Ecology}, volume = {86}, year = {2005}, pages = {2032 -2039}, abstract = {The species{\textendash}area relationship (SAR) plays a central role in biodiversity research, and recent work has increased awareness of its temporal analogue, the species{\textendash} time relationship (STR). Here we provide evidence for a general species{\textendash}time{\textendash}area relationship (STAR), in which species number is a function of the area and time span of sampling, as well as their interaction. For eight assemblages, ranging from lake zooplankton to desert rodents, this model outperformed a sampling-based model and two simpler models in which area and time had independent effects. In every case, the interaction term was negative, meaning that rates of species accumulation in space decreased with the time span of sampling, while species accumulation rates in time decreased with area sampled. Although questions remain about its precise functional form, the STAR provides a tool for scaling species richness across time and space, for comparing the relative rates of species turnover in space and time at different scales of sampling, and for rigorous testing of mechanisms proposed to drive community dynamics. Our results show that the SAR and STR are not separate relationships but two dimensions of one unified pattern.}, keywords = {LTER-KNZ}, doi = {10.1890/05-0067}, author = {P. Adler and White, E.P. and Lauenroth, W.K. and Kaufman, D.M. and Rassweiler, A. and Rusak, J.A.} } @article {KNZ001024, title = {Indicators of plant species richness in AVIRIS spectra of a mesic grassland}, journal = {Remote Sensing of Environment}, volume = {98}, year = {2005}, pages = {304 -316}, abstract = {Hyperspectral imagery of the Konza Prairie Biological Station in northeastern Kansas was used to evaluate upwelling spectral radiance, prairie spectral reflectance and band ratios of each as potential indicators of vascular plant species richness in a mesic grassland. The extent to which spatial variability in these parameters related to plant species richness also was investigated. A 224 channel hyperspectral data cube acquired in June 2000 by the Airborne Visible and Infrared Imaging Spectrometer (AVIRIS) provided complete coverage of the 400{\textendash}2500 nm range at approximately 10 nm per channel. After band deletions accounted for detector overlap and strong atmospheric attenuation features, 176 bands were retained for analysis and spanned the 404{\textendash}2400 nm range. Prairie reflectance was estimated via radiative transfer modeling and scaling to a library spectrum of highway construction material. Data were sampled from pixels having a 19 m ground sample distance (GSD) to represent each of 93 vegetation sampling transects. Reflectance and radiance at mid-infrared wavelengths (e.g., 1553 nm), and band ratios that were based on atmospheric windows in the red, near-infrared and mid-infrared spectra estimated species richness to within 6 to 7 species per transect. The 856 to 780 nm radiance or reflectance ratio yielded maximum adjusted coefficients of determination (r2) of approximately 0.4 in regressions with richness when data from bison-grazed and ungrazed areas were combined. These regressions remained significant (p <= 0.001) when only ungrazed areas were assessed although r2 reduced to approximately 0.2. Richness was related significantly also to the 433 to 674 nm reflectance ratio for grazed-plus-ungrazed and ungrazed-only areas. In contrast, the effectiveness of the 433 to 674 nm radiance ratio was reduced by atmospheric backscatter. Species richness did not correlate strongly or consistently with transect spatial variability (coefficient of variation or range) in radiance, reflectance or band ratio value, apparently as a consequence of the relatively small area sampled for each transect (approximately 0.5 ha). Relationships between richness and prairie spectral features were explained by the influence of soil exposure on both parameters. Richness and estimated soil exposure tended to increase from ungrazed lowlands, to ungrazed slopes, to ungrazed uplands to grazed areas. Remotely sensed estimates of soil exposure may be particularly useful in addressing plant species richness on grazed grasslands owing to an overall similarity in spectral reflectance among dominant plant species.}, keywords = {LTER-KNZ, AVIRIS, Biodiversity, Bison grazing, grassland, Hyperspectral, Plant species richness, Radiance, Reflectance, Soil exposure, Spatial variability, Spectral mixing}, doi = {10.1016/j.rse.2005.08.001}, author = {Carter, G.A. and Alan K. Knapp and Anderson, J.E. and Hoch, G.A. and M.D. Smith} } @article {KNZ00898, title = {Barley yellow dwarf disease in natural populations of dominant tallgrass prairie species in Kansas}, journal = {Plant Disease}, volume = {88}, year = {2004}, pages = {574 -}, abstract = {The grasses Sorghastrum nutans (Indian grass), Schizachyrium scoparium (little bluestem), Panicum virgatum (switchgrass), and Andropogon gerardii (big bluestem) are four of the most common plant species present in a tallgrass prairie (1). Infection with barley yellow dwarf virus (BYDV, family Luteoviridae) is of interest in these species because of the potential effects of the virus on tallgrass prairie plant communities and the potential for tallgrass prairie to function as a reservoir of the virus for infection in wheat or barley fields. In a previous inoculation experiment, an unidentified strain of BYDV transmitted by the aphid species Rhopalosiphum padi was reported to infect S. scoparium but none of the other three grass species (2). We sampled for the presence of five virus strains in at least 50 blooming plants of each grass species in a natural tallgrass prairie stand in August 2000. Samples were collected in watersheds that were designated 1B, 1D, K1A, 20B, and 20C at Konza Prairie Biological Station in the Flint Hills near Manhattan, KS. To detect the virus, we used enzyme-linked immunosorbent assay (ELISA) with antibodies purchased from Agdia (Elkhart, IN). For the PAV, MAV, RMV, and SGV strains, we used double-antibody sandwich ELISA with alkaline phosphatase label. For Cereal yellow dwarf virus (RPV), we used compound direct ELISA with alkaline phosphatase label. The scoring of ELISA results was based on comparison with infected and uninfected control plants of the same species. Symptoms of infection in the field were difficult to interpret visually, since plants in this natural environment often showed multiple symptoms of stress. None of the five strains were detected in 51 individuals of S. nutans. For 50 individuals of S. scoparium, the incidence of infection by the different strains was 4\% for MAV, 0\% for PAV, 2\% for RMV, 0\% for RPV, and 58\% for SGV. For 51 individuals of P. virgatum, the incidence of infection was 31\% for MAV, 0\% for PAV, 0\% for RMV, 0\% for RPV, and 4\% for SGV. For 64 individuals of A. gerardii, the incidence of infection was 59\% for MAV, 0\% for PAV, 0\% for RMV, 0\% for RPV, and 3\% for SGV. The impact of BYDV on these tallgrass prairie species remains to be determined. The PAV strain is the most commonly reported strain in wheat in Kansas but was not recovered from these grass species.}, keywords = {LTER-KNZ}, doi = {10.1094/PDIS.2004.88.5.574B}, author = {Garrett, K.A. and Dendy, S.P. and Power, A.G. and Blaisdell, G.K. and Alexander, H.M. and McCarron, J.K.} } @article {KNZ00943, title = {Generality in ecology: testing North American grassland rules in South African savannas}, journal = {Frontiers in Ecology and the Environment}, volume = {9}, year = {2004}, pages = {483 -491}, abstract = {Ecology has emerged as a global science, and there is a pressing need to identify ecological rules {\textendash} general principles that will improve its predictive capability for scientists and its usefulness for managers and policy makers. Ideally, the generality and limits of these ecological rules should be assessed using extensive, coordinated experiments that ensure consistency in design and comparability of data. To improve the design of these large-scale efforts, existing data should be used to test prospective ecological rules and to identify their limits and contingencies. As an example of this approach, we describe prospective rules for grassland responses to fire and rainfall gradients, identified from long-term studies of North American grasslands and tested with existing data from long-term experiments in South African savanna grasslands. Analyses indicated consistent effects of fire on the abundance of the dominant (grasses) and subdominant (forbs) flora on both continents, but no common response of grass or forb abundance across a rainfall gradient. Such analyses can inform future research designs to refine and more explicitly test ecological rules.}, keywords = {LTER-KNZ}, doi = {10.1890/1540-9295(2004)002[0483:GIETNA]2.0.CO;2}, author = {Alan K. Knapp and M.D. Smith and Scott. L. Collins and Zambatis, N. and Peel, M. and Emery, S.M. and Wojdak, J. and Horner-Devine, M.C. and Biggs, H. and Kruger, J. and Andelman, S.J.} } @article {KNZ00957, title = {Invasion in space and time: non-native species richness and relative abundance respond to interannual variation in productivity and diversity}, journal = {Ecology Letters}, volume = {7}, year = {2004}, pages = {947 -957}, abstract = {Ecologists have long sought to understand the relationships among species diversity, community productivity and invasion by non-native species. Here, four long-term observational datasets were analyzed using repeated measures statistics to determine how plant species richness and community resource capture (i.e. productivity) influenced invasion. Multiple factors influenced the results, including the metric used to quantify invasion, interannual variation and spatial scale. Native richness was positively correlated with non-native richness, but was usually negatively correlated with non-native abundance, and these patterns were stronger at the larger spatial scale. Logistic regressions indicated that the probability of invasion was reduced both within and following years with high productivity, except at the desert grassland site where high productivity was associated with increased invasion. Our analysis suggests that while non-natives were most likely to establish in species rich communities, their success was diminished by high resource capture by the resident community.}, keywords = {LTER-KNZ}, doi = {10.1111/j.1461-0248.2004.00655.x}, author = {Cleland, E.E. and M.D. Smith and Andelman, S.J. and Bowles, C. and Carney, K.M. and Horner-Devine, M.C. and Drake, J.M. and Emery, S.M. and Gramling, J.M. and Vandermast, D.B.} } @article {KNZ00845, title = {The importance of land-use legacies to ecology and conservation}, journal = {BioScience}, volume = {53}, year = {2003}, pages = {77 -88}, abstract = {Recognition of the importance of land-use history and its legacies in most ecological systems has been a major factor driving the recent focus on human activity as a legitimate and essential subject of environmental science. Ecologists, conservationists, and natural resource policymakers now recognize that the legacies of land-use activities continue to influence ecosystem structure and function for decades or centuries{\textemdash}or even longer{\textemdash}after those activities have ceased. Consequently, recognition of these historical legacies adds explanatory power to our understanding of modern conditions at scales from organisms to the globe and reduces missteps in anticipating or managing for future conditions. As a result, environmental history emerges as an integral part of ecological science and conservation planning. By considering diverse ecological phenomena, ranging from biodiversity and biogeochemical cycles to ecosystem resilience to anthropogenic stress, and by examining terrestrial and aquatic ecosystems in temperate to tropical biomes, this article demonstrates the ubiquity and importance of land-use legacies to environmental science and management.}, keywords = {LTER-KNZ, conservation, disturbance, ecosystem process, Land use, natural resource management}, doi = {10.1641/0006-3568(2003)053[0077:TIOLUL]2.0.CO;2}, author = {D.R. Foster and Swanson, F. and Aber, J. and I. Burke and Brokaw, N. and Tilman, D. and Alan K. Knapp} } @article {KNZ00882, title = {Nitrogen enrichment alters mycorrhizal allocation at five mesic to semiarid grasslands}, journal = {Ecology}, volume = {84}, year = {2003}, pages = {1895 -1908}, abstract = {Arbuscular mycorrhizal (AM) fungi are integral components of grasslands because most plants are associated with interconnected networks of AM hyphae. Mycorrhizae generally facilitate plant uptake of nutrients from the soil. However, mycorrhizal associations are known to vary in their mutualistic function, and there is currently no metric that links AM functioning with fungal colonization of roots. Mycorrhizal structures differ in their physiological and ecological functioning, so changes in AM allocation to intraradical (inside roots) and extraradical (in soil) structures may signal shifts in mycorrhizal function. We hypothesize that the functional equilibrium model applies to AM fungi and that fertilization should reduce allocation to arbuscules, coils, and extraradical hyphae, the fungal structures that are directly involved in nutrient acquisition and transfer to plants. This study compared AM responses to experimental N enrichment at five grasslands distributed across North America. Samples were collected from replicated N-enriched (and some P-enriched) and control plots throughout the growing season for three years. Intraradical AM structures were measured in over 1400 root samples, extraradical hyphal density was measured in over 590 soil samples, and spore biovolume was analyzed in over 400 soil samples. There were significant site {\texttimes} N interactions for spore biovolume, extraradical hyphae, intraradical hyphae, and vesicles. Nitrogen enrichment strongly decreased AM structures at Cedar Creek, the site with the lowest soil N:P, and it increased AM structures at Konza Prairie, the site with the highest soil N:P. As predicted by the functional equilibrium model, in soils with sufficient P, relative allocation to arbuscules, coils, and extraradical hyphae was generally reduced by N enrichment. Allocation to spores and hyphae was most sensitive to fertilization. At the mesic sites, this response was associated with a shift in the relative abundance of Gigasporaceae within AM fungal communities. This study demonstrates that N enrichment impacts mycorrhizal allocation across a wide range of grassland ecosystems. Such changes are important because they suggest an alteration in mycorrhizal functioning that, in turn, may impact plant community composition and ecosystem function.}, keywords = {LTER-KNZ}, doi = {10.1890/0012-9658(2003)084[1895:NEAMAA]2.0.CO;2}, author = {Johnson, N.C. and Rowland, D.L. and Corkidi, L. and Egerton-Warburton, L.M. and Allen, E.B.} } @article {KNZ00859, title = {Spatial heterogeneity in the herbaceous layer of a semi-arid savanna ecosystem}, journal = {Plant Ecology}, volume = {167}, year = {2003}, pages = {319 -332}, abstract = {Despite increasing recognition of the role spatial pattern can play in ecosystem function, few studies have quantified spatial heterogeneity in savanna ecosystems. The spatial distribution of herbaceous biomass and species composition was measured across three scales in a semi-arid savanna in central Kenya, and patterns were related to environmental variables at different scales. Herbaceous biomass declined across a rainfall gradient and from upper to lower topographic positions, but variation within a site (across 5{\textendash}50 m) was similar in magnitude to among-site variation associated with rainfall and topography. Geostatistical analyses showed that patchiness at scales of 5{\textendash}25 m explained 20\% of total variation in herbaceous biomass. This pattern arose from the presence of both 5{\textendash}10-m diameter patches containing high herbaceous biomass (> 170 g m-2) and 5{\textendash}10-m diameter patches characterized by nearly bare soil surfaces (< 40 g m-2). Patch structure was contingent on topography, with larger bare patches at ridgeline and upper hillslope positions. Grass species distributions showed the greatest degree of patch structure and species turnover across distances of 5{\textendash}45 m. Additional community variation was associated with topography, with minimal variation in species composition across the rainfall gradient. Pattern diversity significantly exceeded levels reported for four other grassland ecosystems, suggesting fundamental differences in local processes generating spatial pattern. It is hypothesized that heterogeneously distributed grazing pressure, interacting with the distribution of shrub canopies, is an important factor generating such high levels of small-scale patch structure in this savanna.}, keywords = {LTER-KNZ, Geostatistics, Laikipia, Pattern diversity, Plant community patch structure, topography, Ungulate grazing}, doi = {10.1023/A:1023927512590}, author = {Augustine, D.J.} } @article {KNZ00780, title = {Inter-biome comparison of factors controlling stream metabolism}, journal = {Freshwater Biology}, volume = {46}, year = {2001}, pages = {1503 -1517}, abstract = {1. We studied whole-ecosystem metabolism in eight streams from several biomes in North America to identify controls on the rate of stream metabolism over a large geographic range. The streams studied had climates ranging from tropical to cool-temperate and from humid to arid and were all relatively uninfluenced by human disturbances. 2. Rates of gross primary production (GPP), ecosystem respiration (R) and net ecosystem production (NEP) were determined using the open-system, two-station diurnal oxygen change method. 3. Three general patterns in metabolism were evident among streams: (1) relatively high GPP with positive NEP (i.e. net oxygen production) in early afternoon, (2) moderate primary production with a distinct peak in GPP during daylight but negative NEP at all times and (3) little or no evidence of GPP during daylight and a relatively constant and negative NEP over the entire day. 4. Gross primary production was most strongly correlated with photosynthetically active radiation (PAR). A multiple regression model that included log PAR and stream water soluble reactive phosphorus (SRP) concentration explained 90\% of the variation in log GPP. 5. Ecosystem respiration was significantly correlated with SRP concentration and size of the transient storage zone and, together, these factors explained 73\% of the variation in R. The rate of R was poorly correlated with the rate of GPP. 6. Net ecosystem production was significantly correlated only with PAR, with 53\% of the variation in log NEP explained by log PAR. Only Sycamore Creek, a desert stream in Arizona, had positive NEP (GPP: R > 1), supporting the idea that streams are generally net sinks rather than net sources of organic matter. 7. Our results suggest that light, phosphorus concentration and channel hydraulics are important controls on the rate of ecosystem metabolism in streams over very extensive geographic areas.}, keywords = {LTER-KNZ}, doi = {10.1046/j.1365-2427.2001.00773.x}, author = {Mulholland, P.J. and Fellows, C.S. and Tank, J.L. and Grimm, N.B. and Webster, J.R. and Hamilton, S.K. and Marti, E. and L.R. Ashkenas and W.B. Bowden and W. K. Dodds and W.H. McDowell and Paul, M.J. and Peterson, B.J.} } @article {KNZ0015, title = {Sexual segregation results in differences in content and quality of bison (Bos bison) diets}, journal = {Journal of Mammalogy}, volume = {82}, year = {2001}, pages = {407 -413}, abstract = {We examined diets of bison (Bos bison) bulls, cows, juveniles, and calves to determine differences in quality of diets between groups. Our results showed that bulls had a significantly higher proportion of C4 grasses in their diet than cows, juveniles, or calves. Diets of calves were of higher quality than diets of bulls, cows, or juveniles. Our results provide support for the sexual dimorphism{\textendash}body size hypothesis of sexual segregation in large ungulates.}, keywords = {LTER-KNZ, bison, Bos bison, diet composition, diet quality, sexual segregation}, doi = {http://dx.doi.org/10.1644/1545-1542(2001)082<0407:SSRIDI>2.0.CO;2 }, author = {Post, D.M. and Armbrust, T.A. and Horne, E.A. and Goheen, J.} } @article {KNZ00705, title = {Biomass production and species composition change in a tallgrass prairie ecosystem after long-term exposure to elevated atmospheric CO2}, journal = {Global Change Biology}, volume = {5}, year = {1999}, pages = {497 -506}, abstract = {To determine the long-term impact of elevated CO2 on primary production of native tallgrass prairie, we compared the responses of tallgrass prairie at ambient and twice-ambient atmospheric CO2 levels over an 8-year period. Plots in open-top chambers (4.5 m diameter) were exposed continuously (24 h) to ambient and elevated CO2 from early April to late October each year. Unchambered plots were monitored also. Above-ground peak biomass was determined by clipping each year in early August, and root growth was estimated by harvesting roots from root ingrowth bags. Plant community composition was censused each year in early June. In the last 2 years of the study, subplots were clipped on 1 June or 1 July, and regrowth was harvested on 1 October. Volumetric soil water content of the 0{\textendash}100 cm soil layer was determined using neutron scattering, and was generally higher in elevated CO2 plots than ambient. Peak above-ground biomass was greater on elevated CO2 plots than ambient CO2 plots with or without chambers during years with significant plant water stress. Above-ground regrowth biomass was greater under elevated CO2 than under ambient CO2 in a year with late-season water stress, but did not differ in a wetter year. Root ingrowth biomass was also greater in elevated CO2 plots than ambient CO2 plots when water stress occurred during the growing season. The basal cover and relative amount of warm-season perennial grasses (C4) in the stand changed little during the 8-year period, but basal cover and relative amount of cool-season perennial grasses (C3) in the stand declined in the elevated CO2 plots and in ambient CO2 plots with chambers. Forbs (C3) and members of the Cyperaceae (C3) increased in basal cover and relative amount in the stand at elevated compared to ambient CO2. Greater biomass production under elevated CO2 in C4-dominated grasslands may lead to a greater carbon sequestration by those ecosystems and reduce peak atmospheric CO2 concentrations in the future.}, keywords = {LTER-KNZ, tallgrass prairie}, doi = {10.1046/j.1365-2486.1999.00245.x}, author = {Owensby, C.E. and J.M. Ham and Alan K. Knapp and Auen, L.M.} } @article {KNZ00671, title = {Changes in enzyme activities and microbial biomass of tallgrass prairie soil as related to burning and nitrogen fertilization}, journal = {Soil Biology \& Biochemistry}, volume = {31}, year = {1999}, pages = {769 -777}, abstract = {Microbial biomass and enzyme activities are affected by management practices and can be used as sensitive indicators of ecological stability. Microbial biomass C (MBC), microbial biomass N (MBN) and eight enzyme activities involved in the cycling of C, N, P and S were studied in the surface (0{\textendash}5 cm) of an Irwin silty clay loam soil (fine, mixed, mesic, Pachic Arguistoll) in a tallgrass prairie ecosystem. Treatments of annual spring burning and N fertilization were initiated in 1986 and encompassed: (1) unburned{\textendash}unfertilized, (2) burned{\textendash}unfertilized, (3) burned{\textendash}fertilized, and (4) unburned{\textendash}fertilized. Activities of dehydrogenase, β-glucosidase, urease, deaminase, denitrifying enzyme, acid phosphatase, alkaline phosphatase, and arylsulfatase were assayed. Long-term burning and N fertilization of the tallgrass prairie soil reduced MBC and MBN relative to the unburned{\textendash}unfertilized treatment. The effects of burning and N fertilization varied among the enzymes and the time of sampling. Long-term burning significantly (P<0.05) increased activities of urease and acid phosphatase, but decreased activities of β-glucosidase, deaminase and alkaline phosphatase. Long-term N fertilization significantly increased activities of β-glucosidase and acid phosphatase but decreased urease activity. This study found that several soil enzyme activities can be used as indicators of ecological changes caused by N fertilization and long-term burning management practices. The relevance of these changes in surface soil to the long-term sustainability of this ecosystem needs further evaluation.}, keywords = {LTER-KNZ, tallgrass prairie}, doi = {10.1016/S0038-0717(98)00177-1}, author = {Ajwa, H.A. and Dell, C.J. and C. W. Rice} } @article {KNZ00618, title = {Carbon and nitrogen mineralization in tallgrass prairie and agricultural soil profiles}, journal = {Soil Science Society of America Journal}, volume = {62}, year = {1998}, pages = {942 -951}, abstract = {In situ mineralization of N may contribute significantly to total inorganic-N pools deep in the soil profile. We conducted long-term laboratory incubation experiments to evaluate the net C and N mineralization in soils collected from various depths in tallgrass prairie and agricultural fields of the same geological materials and soil type. Samples were packed to a bulk density of 1.4 g cm-3 in 5-cm-diameter by 10-cm-long cores. The cores were incubated at 35{\textdegree}C for 40 wk in sealed containers. Net C mineralization was measured by evolved CO2, and N mineralized was measured by periodic leaching with NH+4 and NO-3 measured in the leachate. Carbon and N mineralization in the surface horizon were greater in the tallgrass prairie than in the agricultural soil. In both the tallgrass prairie and agricultural soil profiles, C mineralization was least at the water-table depth. Carbon mineralization was described by a first-order kinetic model, but N mineralization was described better by a consecutive (sigmoidal) reaction model. At most depths, the ratios of potentially mineralizable organic C (C0) to total organic C (C0/TOC) and potentially mineralizable organic N (N0) to total N (N0/TN) were greater in the agricultural soil profile than in the tallgrass prairie soil profile. The C0 and N0 in the surface soil (0{\textendash}0.2 m) represented 11.6 and 12.2\% of the total organic C and N pools for the tallgrass prairie soil profile, respectively, and 21.0 and 10.2\% of the total organic C and N pools for the agricultural soil profile. Management practices affected the mineralization potentials and rates of both the surface and subsurface soils.}, keywords = {LTER-KNZ, tallgrass prairie}, doi = {10.2136/sssaj1998.03615995006200040014x}, author = {Ajwa, H.A. and C. W. Rice and Sotomayor, D.} } @article {KNZ00619, title = {Description of the larval stages of Heterosternuta diversicornis (Sharp) Coleoptera: Dytiscidae, Hydroporinae}, journal = {Entomologica Scandinavica}, volume = {29}, year = {1998}, pages = {39 -46}, abstract = {Description of structures of all three larval instars of Heterosternuta diversicornis (Sharp) is presented. The chaetotaxy and porotaxy of the cephalic capsule, head appendages, legs, last abdominal segment, and urogomphi are discussed in detail. A close similarity between larvae of H. diversicornis, H. wickhami Zaitzev and H. cocheconis (Fall) is confirmed. All three species distinguish from the closely related species of the genus Neoporus Guignot by (i) a very short and constricted siphon, (ii) the primary setae FE8 and FE9 which are subequal in length to the maximum width of the metafemur (first instar), (iii) the absence of natatory setae on all tibiae and tarsi, and (iv) the contiguous position of the primary setae UR2 and UR3 on the urogomphomere 1.}, keywords = {LTER-KNZ}, doi = {10.1163/187631298X00186}, author = {Alarie, Y. and Fritz, K.M.} } @article {KNZ00608, title = {Water vapor fluxes and their impact under elevated CO2 in a C4 tallgrass prairie}, journal = {Global Change Biology}, volume = {3}, year = {1997}, pages = {189 -195}, abstract = {We measured leaf-level stomatal conductance, xylem pressure potential, and stomate number and size as well as whole plant sap flow and canopy-level water vapour fluxes in a C4-tallgrass prairie in Kansas exposed to ambient and elevated CO2. Stomatal conductance was reduced by as much as 50\% under elevated CO2 compared to ambient. In addition, there was a reduction in stomate number of the C4 grass, Andropogon gerardii Vitman, and the C3 dicot herb, Salvia pitcheri Torr., under elevated CO2 compared to ambient. The result was an improved water status for plants exposed to elevated CO2 which was reflected by a less negative xylem pressure potential compared to plants exposed to ambient CO2. Sap flow rates were 20 to 30\% lower for plants exposed to elevated CO2 than for those exposed to ambient CO2. At the canopy level, evapotranspiration was reduced by 22\% under elevated CO2. The reduced water use by the plant canopy under elevated CO2 extended the photosynthetically-active period when water became limiting in the ecosystem. The result was an increased above- and belowground biomass production in years when water stress was frequent.}, keywords = {LTER-KNZ, tallgrass prairie}, doi = {10.1046/j.1365-2486.1997.00084.x}, author = {Owensby, C.E. and J.M. Ham and Alan K. Knapp and D. Bremer and Auen, L.M.} } @inbook {KNZ00564, title = {Ecosystem level responses of tallgrass prairie to elevated CO2}, booktitle = {Carbon Dioxide and Terrestrial Ecosystems}, year = {1996}, pages = {147 -162}, publisher = {Academic Press}, organization = {Academic Press}, address = {London}, keywords = {LTER-KNZ, tallgrass prairie}, author = {Owensby, C.E. and J.M. Ham and Alan K. Knapp and C. W. Rice and Coyne, P.I. and Auen, L.M.}, editor = {Koch, G.W and Mooney, H.A.} } @article {KNZ00571, title = {Elucidation of factors associated with the maturity related decline in degradability of big bluestem cell wall}, journal = {Journal of Animal Science}, volume = {74}, year = {1996}, pages = {648 -657}, abstract = {Big bluestem (Andropogon gerardii) forage samples were collected from three ungrazed, annually burned pastures at 38, 58, and 97 d after burning. Cell wall material received five treatments: chlorite delignification, chlorite delignification plus alkali extraction, NaOH, NaOCH3 in methanol, or NaBH4. Untreated and treated cell walls were analyzed for carbohydrate composition (glucose, xylose, arabinose, galactose, and uronic acids), acetyl bromide lignin, acid detergent lignin, alkali-labile phenolics (p-coumaric and ferulic acids), acetyl groups, and 24- and 72-h in vitro degradabilities of neutral monosaccharides. A number of compositional features, notably concentrations of xylose, core lignin as measured by acetyl bromide lignin, alkali-labile phenolics, and acetyl groups, were well related to the decline in cell wall degradability that occurred with increasing maturity of big bluestem. p-Coumaric acid increased with increasing maturity to a greater extent than did ferulic acid. Acid detergent lignin was not well related to degradability of the cell wall for either the untreated or chemically treated cell walls. Chemical treatments failed to identify any particular cell wall component as being most inhibitory. However, all treatments improved in vitro degradability of the carbohydrate fraction, indicating that components contributing to the undegradability of big bluestem cell wall are sensitive to chemical alteration. Treatments involving alkali were most effective for improving degradability of big bluestem cell walls.}, keywords = {LTER-KNZ}, url = {https://dl.sciencesocieties.org/publications/jas/abstracts/74/3/648}, author = {Titgemeyer, E.C. and Cochran, R.C. and Towne, E.G. and Armendariz, C.K. and K.C. Olson} } @inbook {KNZ00565, title = {Global grassland ecosystem modelling: development and test of ecosystem models for grassland systems}, booktitle = {Global Change: Effects on Coniferous Forests and Grasslands}, year = {1996}, pages = {229 -270}, publisher = {Wiley and Sons}, organization = {Wiley and Sons}, address = {Chichester}, keywords = {LTER-KNZ}, author = {Parton, W.J. and Coughenour, M.B. and Scurlock, J.M.O. and Ojima, D.S. and Gilmanov, T.G. and Scholes, R.J. and Schimel, D.S. and Kirchner, T.B. and Menaut, J.C. and Seastedt, T.R. and Moya, E.G. and Kamnalrut, A. and Kinyamario, J.I. and Hall, D.O.}, editor = {Breymeyer, A.I. and Hall, D.O. and Melillo, J.M. and Agren, G.I.} } @inbook {KNZ00563, title = {Impact of climate and atmospheric carbon dioxide changes on grasslands of the world}, booktitle = {Global Change: Effects on Coniferous Forests and Grasslands}, year = {1996}, pages = {271 -312}, publisher = {Wiley and Sons}, organization = {Wiley and Sons}, address = {Chichester}, keywords = {LTER-KNZ}, author = {Ojima, D.S. and Parton, W.J. and Coughenour, M.B. and Scurlock, J.M.O. and Kirchener, T.B. and Kittel, T.G.F. and Hall, D.O. and Schimel, D.S. and Moya, E.G. and Gilmanov, T.G. and Seastedt, T.R. and Kamnalrut, A. and Kinyamario, J.I. and Long, S.P. and Menaut, J.C. and Sala, O.E. and Scholes, R.J. and van Veen, J.A.}, editor = {Breymeyer, A.I. and Hall, D.O. and Melillo, J.M. and Agren, G.I.} } @proceedings {KNZ00576, title = {New technologies for remote sensing of ecosystem change in rangelands}, journal = {Rangelands in A Sustainable Biosphere}, year = {1996}, pages = {139 -142}, abstract = {The collective area of rangelands, 40-50\% of the global land surface, presents significant logistical challenges for obtaining ecological data for large, heterogeneous areas quickly, cheaply and with a significant level of accuracy. The use of remote sensing for rangeland monitoring and scaling up from plot to region is reviewed. A major challenge in remote sensing applications lies with assessing ecosystem function from spectral measurements of ecosystem structure. New methods which may assist in the identification and tracking of rangeland response to management practices at the regional scale and provide information on vegetation structure at the continental scale are described. On-going attempts to develop a coupled remote sensing rangeland ecosystem modelling approach for monitoring structure and quantifying energy flow and nutrient cycling are described and examples using Konza Prairie, Kansas, USA data are given}, keywords = {LTER-KNZ}, author = {Wessman, C.A. and Schimel, D.S. and S.R. Archer and Bateson, C.A. and Braswell, B.H. and Ojima, D.S. and Parton, W.J. and West, N.E.} } @article {KNZ0014, title = {Regional climatic similarities in the temperate zones of North and South America}, journal = {Journal of Biogeography}, volume = {22}, year = {1995}, pages = {915 -925}, abstract = {


}, keywords = {LTER-KNZ, climate}, url = {http://www.jstor.org/stable/2845992}, author = {Paruelo, J.M. and Lauenroth, W.K. and Epstein, H.E. and Burke, I.C. and Aguiar, M.R. and Sala, O.E.} } @article {KNZ00432, title = {Mycorrhizal dependence of Andropogon gerardii and Schizachyrium scoparium in two prairie soils}, journal = {American Midland Naturalist}, volume = {132}, year = {1994}, pages = {366 -376}, abstract = {Previous research in tallgrass prairie in Kansas indicated that warm-season, C4, grasses are obligate mycotrophs and do not grow normally in the absence of mycorrhizal symbiosis. However, the degree to which such grasses depend on mycorrhizae in other prairie soils has not been examined. Growth and mycorrhizal colonization of roots of Andropogon gerardii and Schizachyrium scoparium were compared in soil collected from Konza Prairie Research Natural Area (KPRNA), Riley County, Kansas and from Sand Ridge State Forest (SRSF), Mason County, Illinois. Plants of both species were grown in the two soils and were inoculated with Glomus etunicatum spores originally collected from KPRNA or colonized root pieces from S. scoparium plants collected from SRSF. Glomus etunicatum inoculum resulted in significantly greater root colonization and biomass of both plant species in steamed KPRNA soil than did root piece inoculum. There was no benefit from inoculation in non-sterile soil which contained indigenous mycorrhizal fungi. In SRSF soil, there was no response to inoculation with mycorrhizal fungi from either source. The lack of mycorrhizal response in SRSF soil is attributed to the greater plant-available P level of this soil. For S. scoparium grown in SRSF soil, plants grown in steamed soil produced more biomass than plants grown in steamed soil amended with nonsterile soil sievings (containing soil organisms other than mycorrhizal fungi), or in nonsterile soil. These differences could be due to competition for inorganic nutrients between soil microbes and the plant or antagonistic relationships between the plant or the mycorrhizal association and the soil microbes. Thus, the mycorrhizal dependence of these plant species is related to both soil and inoculum type or species.}, keywords = {LTER-KNZ}, doi = {10.2307/2426592}, author = {Anderson, R.C. and Hetrick, B.A.D. and G.T. Wilson} } @article {KNZ00417, title = {Biomass production in a tallgrass prairie ecosystem exposed to ambient and elevated CO2}, journal = {Ecological Applications}, volume = {3}, year = {1993}, pages = {644 -653}, keywords = {LTER-KNZ, Aboveground biomass, Andropogon gerardii, Carbon dioxide, elevated CO2, kansas, Poa pratensis, Root biomass, tallgrass prairie, water-use efficiency, xylem pressure potential}, doi = {10.2307/1942097}, author = {Owensby, C.E. and Coyne, P.I. and Ham, J.M. and Auen, L.M. and Alan K. Knapp} } @article {KNZ00386, title = {Mechanisms and processes in vegetation dynamics: Introduction}, journal = {Journal of Vegetation Science}, volume = {4}, year = {1993}, pages = {146 -148}, keywords = {LTER-KNZ}, doi = {10.1111/j.1654-1103.1993.tb01885.x}, author = {Agnew, A.D.Q. and Scott. L. Collins and Maarel, E.} } @article {KNZ00387, title = {Water relations of Juniperus virginiana and Andropogon gerardii in an unburned tallgrass prairie watershed}, journal = {Southwestern Naturalist}, volume = {38}, year = {1993}, pages = {325 -330}, abstract = {We assessed several factors influencing the success of Juniperus virginiana in unburned tallgrass prairie by mapping the distribution of individuals in a 21-ha watershed on the Konza Prairie Research Natural Area in NE Kansas. We also compared the water relations of this tree with those of the dominant grass Andropogon gerardii. No general relationships were detected between the distribution of J. virginiana and plant water status, plant size, soil type, slope, aspect or elevation. Leaf xylem pressure potential (ψ) in upland trees was significantly lower (0.44 MPa) than in lowland trees, but only during the driest portion of the growing season. In contrast, topographic position influenced ψ more strongly in A. gerardii with ψ in upland plants as much as 1.0 MPa lower than in lowland plants. During wetter periods, photosynthetic rates in A. gerardii were higher than in J. virginiana in uplands, but the reverse occurred during the driest period of the growing season. The ability of J. virginiana to maintain higher ψ and higher photosynthetic rates relative to A. gerardii during periods of water limitation may contribute to its success in tallgrass prairie protected from fire.}, keywords = {LTER-KNZ, Water relations}, doi = {10.2307/3671610}, author = {Axmann, B.D. and Alan K. Knapp} } @booklet {KNZ00379, title = {Collected data of the first ISLSCP field experiment: Volume 2: Satellite Imagery 1987-1989}, year = {1992}, keywords = {LTER-KNZ, ISLSCP}, author = {Strebel, D.E. and Landis, D.R. and Newcomer, J.A. and Elburg-Obler, D. and Meeson, B.W. and Agbu, P.A.} } @booklet {KNZ00381, title = {Collected data of the first ISLSCP field experiment: Volume 3: NS001 Imagery 1987 to 1989}, year = {1992}, keywords = {LTER-KNZ, ISLSCP}, author = {Strebel, D.E. and Landis, D.R. and Newcomer, J.A. and Goetz, S.J. and Meeson, B.W. and Agbu, P.A. and McManus, J.M.P.} } @booklet {KNZ00380, title = {Collected data of the first ISLSCP field experiment: Volume 4: ASAS; PBMR Imagery 1987-1989}, year = {1992}, keywords = {LTER-KNZ, ISLSCP}, author = {Strebel, D.E. and Landis, D.R. and Newcomer, J.A. and Meeson, B.W. and Agbu, P.A. and McManus, J.M.P.} } @article {KNZ00344, title = {Fire and the development of oak forests}, journal = {BioScience}, volume = {42}, year = {1992}, pages = {346 -353}, abstract = {

Fire, whether it has occurred to a low, moderate, or high degree, seems to be the common denominator for the development of oak forests on upland sites and their past and present ecological status. This article reviews pre- and postsettlement forest conditions for the major oak dominated ecosystems throughout eastern North America to discern how the influence of fire and human activity have affected the past and present ecology of oak forests and how these factors will likely continue to affect forests in the future

}, keywords = {LTER-KNZ, fire}, doi = {http://www.jstor.org/stable/1311781}, author = {Abrams, M.D.} } @proceedings {KNZ00302, title = {Effects of fire exclusion on tallgrass prairie and gallery forest communities in eastern Kansas}, year = {1991}, pages = {3 -10}, publisher = {Southeastern Forest Experiment Station}, abstract = {


}, keywords = {LTER-KNZ, tallgrass prairie}, author = {Abrams, M.D. and D.J. Gibson}, editor = {Nodvin, S.C. and Waldrop, T.A.} } @inbook {KNZ00296, title = {Satellite remote sensing and field experiments}, booktitle = {Remote Sensing of Biosphere Functioning}, year = {1990}, pages = {169 -201}, publisher = {Springer-Verlag}, organization = {Springer-Verlag}, address = {New York, NY}, abstract = {

The past few years have seen an increasing pressure brought to bear on biologists to apply their research efforts to larger spatial scales. The motivation for this pressure has scientific as well as sociopolitical roots. First, from the science viewpoint, it has become apparent that satellite-based and atmospheric observing techniques can allow researchers a different view of biospheric functioning by spatially integrating the effects of biospheric states and fluxes, respectively, at moderate cost

}, keywords = {LTER-KNZ}, author = {Sellers, P.J. and Hall, F.G. and Strebel, D.E. and Asrar, G.A. and Murphy, R.E.}, editor = {Hobbs, R.J. and Mooney, H.A.} } @article {KNZ00214, title = {Measuring and modeling spectral characteristics of a tallgrass prairie}, journal = {Remote Sensing of the Environment}, volume = {27}, year = {1989}, pages = {143 -155}, abstract = {

This study was conducted to evaluate the diurnal and seasonal, spectral reflectance characteristics of burned and unburned areas of a tallgrass prairie, based on field measurements and models of radiation transport in plant canopies. Burning of the senescent vegetation, resulting from the previous years\&$\#$39; growth, is a common management practice, which results in improved productivity and affects the succession of grass species. The burned and unburned grass canopies showed distinctly different, diurnal and seasonal, spectral reflectance characteristics in the visible and infrared regions of the spectrum. These were attributed to the differences in development of the two plant canopies and the azimuthal differences in sensor-sun-canopy positions during field measurements of spectral reflectance. The radiation transfer model properly simulated the diurnal spectral behavior of the two canopies. The simulated, seasonal, spectral reflectance values for the unburned grass canopy were greater than the measured ones, because of limitations in proper representation of the layer of senescent vegetation in the model

}, keywords = {LTER-KNZ, tallgrass prairie}, doi = {10.1016/0034-4257(89)90014-X}, author = {Asrar, G.A. and Myneni, R.B. and Li, Y. and Kanemasu, E.T.} } @article {KNZ00166, title = {Effects of burning regime on buried seed banks and canopy coverage in Kansas tallgrass prairie}, journal = {The Southwestern Naturalist}, volume = {33}, year = {1988}, pages = {65 -70}, abstract = {

Vegetation cover and buried seeds were studied on three upland sites burned at different intervals (unburned, 4-year burn, and annual burn) in tallgrass prairie in northeastern Kansas. Vegetation of all sites (89 species total) was dominated by Andropogon gerardii (76 to 81\% cover). Schizachyrium scoparium and Sorghastrum nutans cover was higher, whereas Poa pratensis and Sporobolus hererolepis cover was lower on more frequently than on less frequently burned sites. A total of 735 seedlings comprising 28 species were recorded in soil samples from the three treatments. Seed density was variable within and between treatments but was generally highest in unburned treatment and lowest in annually burned prairie. Many Sporobolus cryptandrus were recorded in each treatment. The number of forb seedlings was not significantly different between treatments and was dominated by Erigeron strigosus and Oxalis stricta. Many species that germinated from buried seeds were not recorded as vegetation on the site, and much of the vegetation was not represented as seedlings. The scarcity of viable buried seeds of the dominant tallgrasses and forbs suggest that they are highly dependent on vegetative propagation

}, keywords = {LTER-KNZ, tallgrass prairie}, doi = {10.2307/3672089}, author = {Abrams, M.D.} } @article {KNZ00169, title = {Effects of dormant-season herbage removal on Flint Hills rangeland}, journal = {Journal of Range Management}, volume = {41}, year = {1988}, pages = {481 -482}, abstract = {

Intensive-early stocking in the Kansas Flint Hills has greatly increased livestock production efficiency. The potential grazing of regrowth on intensive-early stocked Flint Hills pastures was studied by monthly mowing to 5-cm height form October to April, 1983-1985. Those treatments had no effect on total nonstructural carbohydrates (TNC) in Andropogon gerardii Vitman rhizomes or on herbage production the following seasons. Since there was no reduction in herbage yield for any mowing date, cattle producers can apparently restock IES pastures after 1 October. Key Words: total nonstructural carbohydrates, Andropogon gerardii , winter removal, near-infrared reflectance spectroscopy

}, keywords = {LTER-KNZ}, author = {Auen, L.M. and Owensby, C.E.} } @article {KNZ00167, title = {Effects of prescribed fire on woody vegetation in a gallery forest understory in northeastern Kansas}, journal = {Transactions of the Kansas Academy of Science}, volume = {91}, year = {1988}, pages = {63 -70}, abstract = {

Woody vegetation in the understory of a gallery forest dominated by large bur oak (Quercus macrocarpa) trees in eastern Kansas was surveyed before (1983) and after two years of annual prescribed burning in April (1984 and 1985). Elm (Ulmus spp.) was the dominant reproduction on the area before burning and increased after burning because of prolific basal sprouting. Five rarer species, including bur oak and chinquapin oak (Q. muehlenbergii), were recorded in 1983 or 1984, but were absent in 1985. Sapling density averaged 1200 per ha prior to burning in 1983 and 0.0 after burning in 1984 and 1985. Total shrub cover significantly decreased from 59.9 percent in 1983 to 9.5 percent in 1985, as a result of decreases in buckbrush (Symphoricarpos orbiculatus) and rough-leaf dogwood (Cornus drummondii)

}, keywords = {LTER-KNZ, gallery forest}, doi = {10.2307/3628339}, author = {Abrams, M.D.} } @article {KNZ00207, title = {The first ISLSCP field experiment (FIFE)}, journal = {Bulletin of the American Meteorological Society}, volume = {69}, year = {1988}, pages = {22 -27}, abstract = {

The International Satellite Land Surface Climatology Project (ISLSCP) was initiated to address the research problems associated with interpretation and exploitation of satellite data over the earth\&$\#$39;s land surface. As the project developed, it was recognized that these objectives could not be attained unless there was also a clearer understanding of the biological controls acting on land-surface-atmosphere fluxes

}, keywords = {LTER-KNZ}, doi = {10.1175/1520-0477(1988)069\<0022:TFIFE\>2.0.CO;2}, author = {Sellers, P.J. and Hall, F.G. and Asrar, G.A. and Strebel, D.E. and Murphy, R.E.} } @article {KNZ00165, title = {Genetic variation in leaf morphology and plant and tissue water relations during drought in Cercis canadensis . L}, journal = {Forest Science}, volume = {34}, year = {1988}, pages = {200 -207}, abstract = {

Genetic variation in plant and tissue water relations in response to drought, and in leaf morphology, were examined in greenhouse-grown Cercis canadensis L. (eastern redbud) seedlings originating from seed obtained in three contrasting habitats: a relatively xeric Kansas prairie, a Kansas gallery forest understory, and a relatively mesic Indiana understory. Kansas prairie redbud maintained significantly greater leaf conductance (gwv) during a 13-day drought than did Kansas and Indiana understory redbud, despite similar decreases in leaf water potential in all three sources. Moreover, Kansas paririe redbud had significantly lower osmotic potentials at full and zero turgor compared to Indiana redbud at both the early and later stages of drought. Kansas understory redbud was the only source to undergo a signigicant decrease in relative water content at zero turgor and the bulk modulus of elasticity during drought. Kansas prairie redbud leaver were smaller and thicker and had higher specific leaf mass (i.e., more xerophytic) than understory redbud leaves. Kansas understory redbud had intermediate characteristics in terms of gwv at the early to middle stages of drought, osmotic potentials at high and low leaf water potential, and leaf area and thickness compared to Kansas prairie and Indiana understory redbud. These results suggest that genetically controlled physiological and morphological adaptation has occurred in redbud that should facilitate its survival in greatly contrasting habitats. ADDITIONAL KEY WORDS: Ecophysiology, Kansas prairie, gallery forest, Indiana understory, leaf morphology

}, keywords = {LTER-KNZ, Water relations}, author = {Abrams, M.D.} } @article {KNZ00168, title = {Radiative surface temperatures of the burned and unburned areas in a tallgrass prairie}, journal = {Remote Sensing of the Environment}, volume = {24}, year = {1988}, pages = {447 -457}, abstract = {

This study was comducted in a natrul tallgrass prairie area in the Flint Hills of Kansas. Our objective was to evaluate the surface radiative temperatures of burned and unburned treatments of the grassland as a means of delineating the areas covered by each treatment. Burning is used to remove the senescent vegetation resulting from the previous year\&$\#$39;s growth. Surface temperatures were obtained in situ andby an airborne scanner. Burned and unburned grass canopies had distinctly different diurnal surface radiative temperatures. Measurements of surface energy balance components revealed a difference in partitioning of of the available energy between the two canopies, which resulted in the difference in their measured surface temperatures. The magnitude of this difference is dependent of the time of measurements and topographic conditions

}, keywords = {LTER-KNZ, tallgrass prairie}, doi = {10.1016/0034-4257(88)90018-1}, author = {Asrar, G.A. and Harris, T.R. and Lapitan, R.L. and Cooper, D.I.} } @article {KNZ00202, title = {Results from the push broom microwave radiometer flights over the Konza Prairie in 1985}, journal = {IEEE Transactions on Geoscience and Remote Sensing}, volume = {26}, year = {1988}, pages = {590 -596}, abstract = {

There were four flights of the NASA C-130 aircraft carrying the Push Broom Microwave Radiometer (PBMR) over the Konza Prairie Research Natural Area in eastern Kansas in 1985. Their objective was to observe surface soil moisture variations with the PBMR. The radiometer operates at the 21-cm wavelength and has four beams that sweep out a swath of about 1.2 times the aircraft altitude. The resolution of each beam is 0.3 times the altitude. At the time of the flights the soil conditions ranged from very wet to moist and the microwave emission expressed as brightness temperatures for the burned watersheds ranged from below 200 to about 245 K. The brightness temperatures were correlated (r2 = 0.5) with surface moisture measurements and the slope of the regression is in good agreement with prior results over other grasslands. However, for the unburned watersheds the brightness temperatures were around 270 K and roughly independent of the soil moisture conditions. In these unburned watersheds, a buildup of a thatch layer serves as highly emissive layer above the soil, causing high brightness, especially when wet

}, keywords = {LTER-KNZ}, doi = {10.1109/36.7684}, author = {Schmugge, T.J. and Wang, J.R. and Asrar, G.A.} } @proceedings {KNZ00159, title = {Airborne multispectral observations over burned and unburned prairies}, year = {1987}, pages = {203 -207}, address = {Ann Arbor, MI}, abstract = {

One of the ongoing studies at the Konza Prairie Natural Area (KPNA) in central Kansas is that of determining the effects periodic burning has on the native grassland ecosystem. In this study, watersheds are burned at intervals from one year to ten years or not at all. The Evapotransiration Laboratory at Kansas State University has been studying the multispectral response of burned and unburned watersheds using truck mounted raiometers and microwave scatterometers since 1983. In June 1985, there was a series of 5 flights with the NASA C-130 aircraft over the KPNA. On board the aircraft was the NS001 multispectral scanner, also known as the thematic mapper simulator. It has 7 visible and near IR channels and a thermal IR channels, whose spectral bands were chosen to simulate the thematic mapper on Landsat\&$\#$39;s 4 and 5. The 21-cm Pushbroom Microwave Radiometer (PBMR) was also on board the aircraft for soil and moisture observations. In addition several L- Band SAR images from the NASA CV-990 aircraft were obtained during this period. The spectral differences between the burned and unburned watersheds were clearly observable in all spectral bands including the thermal IR and the microwave. The normalized difference vegetation index (NDVI) using TM bands 3 and 4 was calculated. Values of less than 0.5 were obtained for the unburned watersheds which contained a mixture of senescent and green vegetaion. The NDVI values for the burned watersheds which contained only green vegetation were greater than 0.6. In the thermal IR, 3 to 4 degree Celsius temperature differences between the two treatments were observed at about 2:00 p.m. LST with the burned watersheds being cooler. Large differences between the two treatments were observed in the microwave emissivities derived from the PBMR data. These are attributed to the build-up of a layer of senescent vegetation on the soil surface in the unburned and ungrazed watersheds

}, keywords = {LTER-KNZ}, author = {Schmugge, T.J. and Kanemasu, E.T. and Asrar, G.A.} } @article {KNZ00132, title = {Effect of topographic position and fire on species composition in tallgrass prairie in northeast Kansas}, journal = {The American Midland Naturalist}, volume = {117}, year = {1987}, pages = {442 -445}, abstract = {

Plant species composition was evaluated on shallow upland and deep lowland soils in annually burned and unburned watersheds in an eastern Kansas Flint Hills tallgrass prairie. Species richness was higher in upland than lowland communities. Andropogon gerardii (big bluestem) was dominant on all sites (cover=70-96\%) and was not significantly affected by topographic position or burn treatment, whereas, A. scoparius (little bluestem) and Sorghastrum nutans (Indiangrass) increased with burning. Cover of Panicum virgatum (switchgrass) was higher on lowland soils, but burning differences were not significant. Poa pratensis (Kentucky bluegrass), the dominant cool-season grass, was not affected by topography but was greatly reduced by annual burning. Cover of most forb and woody species was reduced on burned areas but species were differentially affected by topography. One exception was the woody species Amorpha canescens (leadplant), which had its highest cover on burned lowland soils

}, keywords = {LTER-KNZ, tallgrass prairie}, doi = {10.2307/2425988}, author = {Abrams, M.D. and Hulbert, L.C.} } @mastersthesis {KNZ00133, title = {Effects of dormant season herbage removal on Flint Hills rangeland. II. Near-infrared reflectance spectroscopy analysis of total nonstructural carbohydrates in big bluestem rhizomes}, volume = {MS Thesis}, year = {1987}, pages = {1 -52}, school = {Kansas State University}, type = {M.S. Thesis}, address = {Manhattan, KS}, keywords = {LTER-KNZ, remote sensing}, url = {http://krex.k-state.edu/dspace/handle/2097/16786}, author = {Auen, L.M.} } @article {KNZ00131, title = {Leaf structural and photosynthetic pigment characteristics of three gallery-forest hardwood species in northeast Kansas}, journal = {Forest Ecology and Management}, volume = {22}, year = {1987}, pages = {261 -266}, abstract = {

Leaf structural and photosynthetic pigment characteristics were measured in three dominant gallery-forest hardwood species in northeast Kansas, U.S.A. Leaves of Quercus macrocarpa and Q. muehlenbergii (more-xeric, shade-intolerant species) had significantly greater thickness, specific mass, stomatal densities and guard cell lengths than leaves of Celtis occidentalis (more-mesic, shade-tolerant). Except for guard cell lengths, these findings are consistent with differences between xeric and mesic species and shade-intolerant and shade-tolerant species. These gallery-forest species generally had much greater stomatal densities and/or lower guard-cell lengths compared to the same species or genera growing in more mesic forests further in the east of the U.S. Compared to C. occidentalis, the Quercus species had significantly greater total chlorophyll and carotenoids, but similar chlorophyll-a:b ratios. The chlorophyll findings contradict the established idea that shade-tolerant species have greater total chlorophyll and lower chlorophyll-a:b ratios, but may be related to exceptional site and climatic factors

}, keywords = {LTER-KNZ, leaf, photosynthesis, pigment}, doi = {10.1016/0378-1127(87)90110-1}, author = {Abrams, M.D.} } @inbook {KNZ00163, title = {North american forests and grasslands: biotic conservation}, booktitle = {Nature Conservation: The Role of Remnants of Native Vegetation}, year = {1987}, pages = {163 -176}, publisher = {Surrey Beatty and Sons Pry Limited in association with CSIRO and CALM}, organization = {Surrey Beatty and Sons Pry Limited in association with CSIRO and CALM}, abstract = {


}, keywords = {LTER-KNZ, insect}, author = {Whitcomb, R.F.}, editor = {Saunders, D.A. and Arnold, G.W. and Burbidge, A.A. and Hopkins, A.J.M.} } @article {KNZ00130, title = {Assessing grassland biophysical characteristics from spectral measurements}, journal = {Remote Sensing of the Environment}, volume = {20}, year = {1986}, pages = {141 -152}, abstract = {

Remote sensing offers a potential alternative to tedious hand sampling as a means of monitoring vegetation condition and estimating productivity over large areas of grasslands. This sutdy was conducted to assess the use of spectral reflectance measurements in estimating grass canopy leaf area index (LAI) and total above ground green phytomass. Spectral reflectance measurements were made on a tallgrass prairie during 1983 and 1984 with two multiband radiometers. Green leaf-area index and dry matter accumulations (green above-ground phytomass) were measured on the area monitored by the radiometer. Three indices-near infrared to red ratio, greenness, and normalized difference-were computed from spectral reflectance data. The direct relationships between these special reflectance indices and grass biophysical parameters (LAI and phytomass) were site-dependent and year-specific. Indirect methods of estimating LAI and phytomass from estimates of absorbed, phytosynthetically active radiation, based on measurements of grass canopy spectral reflectance, were found to be more consistent across treatments for the two years of this study

}, keywords = {LTER-KNZ, tallgrass prairie}, doi = {10.1016/0034-4257(86)90019-2}, author = {Weiser, R.L. and Asrar, G.A. and Miller, G.P. and Kanemasu, E.T.} } @article {KNZ00110, title = {Distinguishing among tallgrass prairie cover types from measurements of multispectral reflectance}, journal = {Remote Sensing of the Environment}, volume = {19}, year = {1986}, pages = {159 -169}, abstract = {

The heterogeneity in surface cover caused by management practices or natural events complicates monitoring the conditions of grasslands and asseessing their productivity by remote sensing techniques. Statistical procedures were sought that would allow different grassland surface cover types (bare soil,senescent vegetation, and green vegetation) to be distinguished by using measurements of grassland multispectral reflectance. Two procedures, discriminant functions and canonical discriminant analysis, were found suitable for achieving this objective. Linear classification functions and canonical variables were derived, which distinguish between the three cover types. A comparison between two sensor systems, a Barnes multiband radiometer and an Exotech radiometer that simulates the Landsatthematic mapper (TM) and multispectral scanner (MSS) bands, respectively, showed that the separability among the three cover types was substantially improved by the additional and improved spectral features of the Barnes radiometer

}, keywords = {LTER-KNZ, tallgrass prairie}, doi = {10.1016/0034-4257(86)90069-6}, author = {Asrar, G.A. and Weiser, R.L. and Johnson, D.E. and Kanemasu, E.T. and Killeen, J.M.} } @inbook {KNZ00108, title = {Ecological role of fire in gallery forests in eastern Kansas}, booktitle = {Symposium on Prescribed Burning in the Midwest}, year = {1986}, pages = {73 -80}, publisher = {University of Wisconsin-Stevens Point}, organization = {University of Wisconsin-Stevens Point}, address = {Stevens Point, WI}, abstract = {

The historical role of fire was studies in the gallery forests on Konza Prairie in eastern Kansas. Quercus macrocarpa and Celtis occidentalis dominated mesic and/or intermediate sites, whereas Q. muehlenbergii dominated the more xeric sites. An evaluation of fire history using oak species suggest a mean fire interval of 11-20 years or less since the mid-1800s. Nonetheless, a dramatic expansion of the gallery forests has occurred from 1859-1978. It also appears that Q. macrocarpa is being replaced by C. occidentalis on the mesic sites and that Q. muehlenbergii is being replaced by Cercis canadensis on the more xeric sites. Prescribed burning in a Q. macrocarpa dominated stand resulted in an increase in Ulmus spp. sprouts and a reduction in samplings from 1200 per ha to 0 and in shrub cover from 60\% to 9\%. These studies suggest that fire has been an historical factor affecting the distribution, composition and successful dynamics of gallery forests in eastern Kansas

}, keywords = {LTER-KNZ, fire, forest}, author = {Abrams, M.D.}, editor = {Koonce, A.} } @article {KNZ00105, title = {Historical development of gallery forest in northeast Kansas}, journal = {Vegetatio}, volume = {65}, year = {1986}, pages = {29 -37}, abstract = {

Woody vegetation, soils, age-diameter relationships and historical development are described for 18 gallery forest stands on Konza Prairie, a tallgrass prairie reserve in northeast Kansas. Detrended correspondence analysis (DCA) coupled with the importance values of dominant species was used to identify four stand types in these forests: Quercus muehlenbergii, Q. muehlenbergii-Q. macrocarpa, Q. macrocarpa-Q. muehlenbergii, and Celtis occidentalis-Q. macrcocarpa. Location of these groups on the first DCA axis was correlated with decreasing slope and increasing percent silt (i.e. a moisture gradient form xeric to mesic). Shrub cover increased with droughtness and decreased with both stand basal area and total reproduction. Original Land Office Survey suggest a dramatic expansion of gallery forests along the stream channels and ravines during the period from 1859-1939. Further expansion occurred through 1978. Increases in woody vegetation were attributed to decreased fire intensity and frequency since European settlement. Q. macrocarpa and/or Q. muehlenbergii were the oldest and largest trees in each stand, but were poorly represented as young trees and seedlings. In contrast, Celtis occidentalis, Cercis canadensis and Ulmus spp. were well represented as young trees and were vigorously reproducing singly or in combination in all stands. The growth of these species into trees occurred 10 to 30 years after the major recruitment of Q. macrocarpa and Q. muehlenbergii into the tree size class. It suggested that the oaks will be replaced by C. occidentalis on the more mesic sites and by C. canadensis on the more xeric sites. The potential of Ulmus spp. as an overstory dominant is probably limited by the Dutch Elm Disease

}, keywords = {LTER-KNZ, tallgrass prairie}, doi = {10.1007/BF00032124}, author = {Abrams, M.D.} } @article {KNZ00109, title = {Light interception and leaf area estimates from measurements of grass canopy reflectance}, journal = {IEEE Transactions of Geoscience and Remote Sensing}, volume = {GE-24}, year = {1986}, pages = {76 -82}, abstract = {

Grassland is a major component of the Earth\&$\#$39;s available land. The vast area and remoteness of this ecosystem makes it difficult to assess its condition and monitor productivity by traditional methods. Remote sensing potentially offers a rapid nondestructive approach for monitoring such ecosystems. A study was carried out in a tallgrass prairie site near Manhattan, Kansas, during the 1983 and 1984 seasons to investigate the feasibility of estimating light interception and green leaf area index (LAI) from measurements of canopy multispectral reflectance. Greenness (Gn) index was found to be strongly correlated with intercepted photosynthetically active radiation (PAR). Two methods, a direct regression (RGR) and an indirect approach (IND), were used to estimate LAI form Gn index. The LAI values estimated by RGR method were consistently lower than the measured ones; however, good agreement was obtained between the LAI values estimated by IND method and the measured LAI. This suggests that Gn transformation of canopy spectral reflectance is more closely related to the fraction of intercepted PAR by green foliage than the quantity of green LAI

}, keywords = {LTER-KNZ, tallgrass prairie}, doi = {10.1109/TGRS.1986.289590}, author = {Asrar, G.A. and Kanemasu, E.T. and Miller, G.P. and Weiser, R.L.} } @article {KNZ00104, title = {Physiological plasticity in water relations and leaf structure of understory versus open-grown Cercis canadensis in northeastern Kansas}, journal = {Canadian Journal of Forestry Resources}, volume = {16}, year = {1986}, pages = {1170 -1174}, abstract = {

Field and laboratory studies were used to evaluate physiological plasticity in water relations and leaf structural characteristics of Cercis canadensis L. (redbud) saplings growing in a gallery forest understory and an adjacent prairie in eastern Kansas. Two study periods were defined based on high (greater than -0.2 MPa in May) and low (-1.5 MPa in July) predawn soil water potential ( soil) Leaf conductance to water vapor diffusion (gwv) was greater for prairie than understory redbud saplings during both sampling periods (maximum gwv=7.5-8.7 mm s-1) Moreover, gwv for prairie redbud remained high at both high and low soil, but was significantly lower for understory redbud during midday at low soil. Transpiration flux was also higher in the prairie than in the understory site and reach a maximum for prairie redbud (318 mg m-2s-1) in July, in conjunction with high leaf to air vapor pressure deficits (maximum 5.3 kPa). Leaf water potential declined significantly at both sites with decreased soil and the minimum values (-3.0 MPa) were recorded in understory redbud. Leaves of prairie redbud were significantly smaller, thicker, and had higher specific leaf mass and stomatal density than leaves of understory redbud, which are consistent with differences between zeric and mesic species, respectively. These differences in water relations and leaf morphology between understory and prairie redbud suggest a high degree of physiological plasticity for this species in eastern Kansas

}, keywords = {LTER-KNZ, Water relations}, doi = {10.1139/x86-208}, author = {Abrams, M.D.} } @article {KNZ00107, title = {Seasonal water relations of three gallery forest hardwood species in northeast Kansas}, journal = {Forest Science}, volume = {32}, year = {1986}, pages = {687 -696}, abstract = {

Field and laboratory studies were used to evaluate several water relations characteristics for saplings of three species: hackberry (Celtis occidentalis), a mesic, late successional tree, and bur and chinquapin oak (Quercus macrocarpa and Q. muehlenbergii), more xeric, early successional trees growing in a northeast Kansas gallery forest understory during a dry summer. For all species, maximum stomatal conductance (gwv) (8.9-9.5 mm*s-1) was recorded early in the season when soil moisture was greatest. Seasonally, sunlit leaves generally had significantly higher gwv than shaded leaves. Both gwv and leaf water potential decreased during the season in each species, with minimum leaf water potential values ranging from - 2.13 to -2.48 MPa. Seasonally, leaf water potential remained consistently higher than the osmotic potential at zero turgor for each species (minimum values of zero turgor ranged from -2.61 to -3.02 MPa). Hackberry, the most mesic species, experienced the largest seasonal decrease in gwv in both shaded and sunlit leaves (69\% and 78\% reduction, respectively). Moreover, in contrast to the two oaks, a significant seasonal decline in 600 h leaf water potential was shown for hackberry. By season\&$\#$39;s end, hackberry had the lowest gwv and leaf water potential suggesting that this species was better able to utilize late season precipitation. Additional key words: Quercus, Celtis, ecophysiology, prairie, drought

}, keywords = {LTER-KNZ, Water relations}, author = {Abrams, M.D. and Alan K. Knapp} } @article {KNZ00106, title = {A ten-year record of aboveground biomass in a Kansas tallgrass prairie: effects of fire and topographic position}, journal = {American Journal of Botany}, volume = {73}, year = {1986}, pages = {1509 -1515}, abstract = {

Measurements of mid-season live and dead aboveground biomass are reported for a 10 year period (1975- 1984) in a northeast Kansas tallgrass prairie. Study sites included shallow, rocky upland and deep, nonrocky lowland soils in annually burned (April) and unburned watersheds. Lowland sites had significantly greater live biomass than upland sites for both burned and unburned prairie for the 10 year period. Moreover, live biomass was greater on burned than unburned lowland sites, but was not significantly increased by fire on the upland sites. Averaged across upland and lowland sites, mid-season live biomass was 422 g m-2 on annually burned and 364 g m-2 on unburned sites for the 10 year period. Each site had its lowest live biomass value during the severe drought year of 1980 (range=185-299 g m-2). During the study period, live biomass was most strongly correlated with seasonal pan water evaporation (r=-0.45 to -0.82), whereas dead biomass was correlated with the previous years precipitation (r=0.62 and 0.90 for upland and lowland sites, respectively). When aboveground biomass was sampled throughout the 1984 season and separated into several components, biomass of the graminoids was 40\% lower, whereas that of forbs and woody plants was 200-300\% greater in the unburned than in the annually burned site

}, keywords = {LTER-KNZ, tallgrass prairie}, doi = {~http://www.jstor.org/stable/2443856}, author = {Abrams, M.D. and Alan K. Knapp and Hulbert, L.C.} } @article {KNZ0077, title = {Age-diameter relationships of Quercus species in relation to edaphic factors in gallery forests in northeast Kansas}, journal = {Forest Ecology and Management}, volume = {13}, year = {1985}, pages = {181 -193}, abstract = {

Age-diameter relationships were evaluated for Quercus macrocarpa and Q. muehlenbergii in relation to soil and topographic factors in 18 gallery forest stands in northeast Kansas. Tree diameter was significantly correlated with age (r2=0.33- 0.96,P\< 0.05) for Q. macrocarpa and Q. muehlenbergii in 81\% and 85\% of the stands, respectively, when seven or more individuals of either species were surveyed, indicating that variation in growth rates of these species was low within most of the stands. However, considerable variation in growth rates of these species was evident between stands, which was not explained by differences in stand density. High growth rates for Q. macrocarpa were correlated (P\< 0.05) with low topographic slope (r=0.54), and low available soil NH4 (r=0.73) and NO3 (r=0.72, whereas high growth rates for Q. muehlenbergii were correlated with high K (r=0.62), suggesting that edaphic factors influence growth rates of these species

}, keywords = {LTER-KNZ}, doi = {10.1016/0378-1127(85)90033-7}, author = {Abrams, M.D.} } @article {KNZ0097, title = {Chronic effects of a prescribed field application of a carbamate insecticide on bobwhites}, journal = {The World Pheasant Association}, volume = {10}, year = {1985}, pages = {47 -64}, abstract = {

As part of the registration process for agricultural pesticides in the United States, Short-Term Field Tests for Hazard to Birds (small pen studies) are sometimes required for pesticides exhibiting moderate acute toxicity (Environmental Protection Agency 1978). We conducted such a small pen study to determine the chronic hazards of bendiocarb (an insecticide designed to control corn rootworms, trade name TATTOO, Fisons Ltd., Essex, England) to birds. Bendiocarb is a moderately toxic N-methyl N-dimethyl compound typical of the carbamate group of insecticides introduced into the United States in the mid-1950s. The small pen study was conducted with Northern Bobwhites (Colinus virginianus) under normal agricultural conditions. The scope of the study was expanded to include fatty acid analysis of eggs and body tissues of experimental birds, determination of energy content of eggs, quantitative measures of bobwhite mobility and activity, and analysis of brain cholinesterase activity. Major modifications of any of these parameters could pose adverse ecological problems for wild avian populations. This report presents the results of this small pen study and is contribution No. 85-347-J, Division of Biology, Kansas Agricultural Experiment Station, Kansas State University, Manhattan, KS 66502

}, keywords = {LTER-KNZ}, author = {Robel, R.J. and Arruda, S.M. and Morrow, M.E. and O{\textquoteright}Neill, D.H.} } @article {KNZ0091, title = {An evaluation of beta attenuation for estimating aboveground biomass in a tallgrass prairie}, journal = {Journal of Range Management}, volume = {38}, year = {1985}, pages = {556 -558}, abstract = {

The attenuation of beta particles by vegetation was evaluated as a nondestructive method for estimating aboveground biomass in tallgrass prairie in northeast Kansas. Regression equations using the sum of beta attenuation measurements for each of 5 height classes within the vegetation and mean midday leaf water potential as the independent variables were used to predict live and total biomass. Live and total biomass were better predicted on burned (r2=.91 and .88, respectively) and unburned sites (r2=.71 and .70, respectively). Greater variability in the relationship between beta attentuation and biomass in unburned prairie was a result of the large and variable amount of dead biomass on unburned sites. Dead biomass was poorly predicted by beta attentuation (r2=.24- .49). Beta attentuation predicted biomass in burned tallgrass prairie within +/- 5\% of harvest values until late season vegetative senescence. In unburned prairie, predictions were poorer, but the technique could still be useful if the required accuracy need be only +/- 25\%

}, keywords = {LTER-KNZ, tallgrass prairie}, doi = {10.2307/3899752}, author = {Alan K. Knapp and Abrams, M.D. and Hulbert, L.C.} } @article {KNZ0076, title = {Fire history of oak gallery forests in a northeast Kansas tallgrass prairie}, journal = {The American Midland Naturalist}, volume = {114}, year = {1985}, pages = {188 -191}, abstract = {

Bur oak (Quercus macrocarpa) and chinquapin oak (Q. muehlenbergii) were repeatedly scarred from recurring fire in gallery forests on Konza Prairie in NE Kansas, and were therefore suitable for fire history evaluation. Fire scars were recorded in 23 different years, ranging from 1862 to 1983, on 19 sample trees taken from three noncontiguous gallery forest stands. The mean fire interval (MFI) calculated for these forests ranged from 11.2-19.7 years. The actual MFI, however, probably lies somewhere between that range and the historical interval for Flint Hills prairie fire of 2-3 years

}, keywords = {LTER-KNZ, tallgrass prairie}, doi = {10.2307/2425255}, author = {Abrams, M.D.} } @article {KNZ00102, title = {Vesicular-arbuscular mycorrhizae and greenhouse production of three native tallgrass prairie forbs}, journal = {Restoration and Management Notes}, volume = {31}, year = {1985}, pages = {24 -}, abstract = {

Seedlings of Baptistia leucantha (Atlantic wild indigo), Liatris aspera (rough gayfeather), and Asclepias tuberosa (butterfly milkweed) were grown in 165 cc tubes containing 1:1:1 peat:perlite:soil (v) or 1:1 soil:sand (v), both of which had been amended with 0, 41.6 phosphorus, or 83.2 g/P per cubic foot of media in the form of superphosphate (0-46-0). The tubes were inoculated with Glomus etunicatum, G. fasciculatum, G. macrocarpum, G. mossae, or remained uninoculated. After five months total dry weights and percentage root colonization were determined for one-half of the replications. The remaining plants were outplanted in the field to study transplant establishment

}, keywords = {LTER-KNZ, tallgrass prairie}, author = {Zajicek, J.M. and Albrecht, M.L. and Hetrick, B.A.D.} }